The Hidden Costs Draining Your Auto Repair Shop's Profit

When we looked at Lucas Underwood's financials, one expense immediately stood out: nearly $15,000 in warranty costs.

That number prompted Lucas to dig deeper into what was happening at his shop. He discovered approximately $5,200 in work that probably shouldn't have been covered under warranty in the first place.

And that wasn't the only problem hiding in the numbers.

I recently sat down with Lucas Underwood, co-host of Changing the Industry Podcast and owner of L&N Performance Auto Repair, to work through his shop's financials after a difficult start to the year. Between management changes, disruptions to his advertising, and rising costs, things hadn't gone as planned.

Once we started digging into the numbers, we found money tied up in unfinished repairs, pressure on parts margins, and opportunities to improve profitability without necessarily bringing in more customers.

That's why having accurate financial statements matters. They don't just tell you whether your shop made money. They help you figure out where you're losing it and what to do about it.

You Can't Fix a Problem You Can't See

One of the first things Lucas told me was that he'd finally gotten clean financial statements after spending much of the previous year without reliable numbers.

He'd hired a bookkeeper expecting accurate reports and useful information. Instead, he spent months trying to get what he needed.

In the meantime, he was running the business largely on instinct.

Lucas estimated his monthly operating expenses at around $85,000, and he was remarkably close.

But there's a big difference between estimating your expenses and knowing what they are.

If your financials aren't accurate, how do you know whether a slow month is the problem? Or whether you're spending too much on something that's been quietly eating away at your profit?

You don't.

With dependable numbers, we could finally identify what needed attention.

That's why I keep coming back to the importance of accurate monthly financial statements. They're not just reports your accountant prepares. They're tools you should be using to make decisions.

In Lucas's case, those numbers uncovered several problems worth addressing.

1. When Taking Care of Customers Starts Costing You Too Much

I believe a shop should stand behind its work. If you make a mistake, you own it, fix it, and take care of the customer.

But what happens when your team starts treating things as warranty repairs that aren't actually covered by warranty?

Lucas discovered what he called policy creep.

Over time, his team had gotten into the habit of approving work under warranty rather than having difficult conversations with customers.

One example involved brakes that had been severely overheated from driving down the mountain. The customer wasn't happy, but that didn't automatically make it a warranty issue.

When we looked at Lucas's financials, warranty expenses were running around $15,000. That number got our attention.

Lucas had already started digging into the problem operationally. He discovered that approximately $5,200 of those expenses came from work that probably shouldn't have been covered under warranty in the first place.

That included situations like the overheated brakes. Instead of having a difficult conversation with the customer, the shop was absorbing the cost.

That's more than $5,000 that could have stayed in the business simply by making better decisions about what qualified for warranty coverage.

And the problem goes beyond what shows up on the expense report.

Warranty work costs more than parts and labor

Think about what happens when a technician spends three hours working on a vehicle the shop isn't getting paid to repair.

You've got the cost of the technician's time and any parts involved. But you've also tied up three hours that could have been spent producing revenue on another vehicle.

That second piece is the opportunity cost.

Now, I wouldn't automatically count every hour of warranty work as lost revenue. You have to have paying work available, and your shop has to be able to move that work through the process.

But when you've got customers waiting and bays tied up with unnecessary warranty repairs, the impact can be substantial.

Lucas and I discussed bringing his warranty expenses down to approximately 1.5% of sales as an initial working target.

For his shop, that meant getting much more disciplined about what qualified for warranty coverage.

It also meant addressing another issue: quality control.

There's a difference between a legitimate comeback caused by a problem with the original repair and a customer asking you to cover something unrelated. One requires improving the work or the process. The other may require a difficult conversation at the front counter.

You need to understand which problem you're dealing with.

The goal isn't to stop taking care of customers. It's to stop giving away work that shouldn't be free.

2. You've Got $70,000 in Work Sitting in the Parking Lot. Now What?

Here's where the conversation got especially interesting.

Lucas had approximately $70,000 in unfinished work sitting at the shop, with 25 vehicles still waiting to move through the process.

But $70,000 in unfinished work isn't $70,000 in the bank.

Some of those vehicles were waiting on parts. Others were caught up in the shop's workflow. And until the repairs were finished, invoiced, and paid, that work wasn't producing the cash Lucas needed.

Meanwhile, the business still had expenses to cover.

Parts vendors weren't going to wait indefinitely for their money. Payroll wasn't going to stop because a vehicle had been sitting for three weeks.

As I told Lucas during our conversation:

Ultimately, the longer the car sits, it turns you into the bank.

When you pay for parts and labor before you collect from the customer, you're financing that work. The longer the vehicle sits, the longer your cash is tied up.

Why more car count isn't always the answer

When a shop is struggling financially, it's tempting to say, "We need more cars."

Sometimes you do.

But what if your parking lot is already full?

Lucas made a good point about this. His shop had plenty of vehicles on-site. The problem wasn't necessarily getting more cars through the front door. It was getting the cars he already had out the other side.

That's a throughput problem.

Car count measures how many vehicles your shop services. Throughput is about how efficiently those vehicles move through your repair process.

You can have strong car count and still have poor cash flow if vehicles are taking too long to complete.

And sometimes the bottleneck isn't even something you can easily control.

Lucas was dealing with parts availability problems, including situations where he could find inexpensive aftermarket parts but couldn't get the quality parts he was comfortable installing.

I respect that. You don't want to compromise the quality of a repair just to get a vehicle out of the shop.

But you do need to understand what those delays are costing you and look for ways to keep the rest of the work moving.

Technician capacity matters here, too. Knowing what your technicians actually cost and how much labor they're producing helps you see whether your staffing and pricing support the work coming through the shop. Our Labor Costing Tool can help you work through those numbers.

Before you spend more money trying to attract additional customers, ask yourself whether your shop can efficiently handle the work it already has.

3. Your Parts Margins May Be Shrinking Without You Realizing It

When we reviewed Lucas's profit and loss statement, his overall gross profit was around 53%. His labor gross profit was relatively healthy, but his parts cost was running at approximately 50% of parts sales.

That left him with about a 50% parts gross profit margin.

Parts costs have been increasing, and customers have more ways than ever to question what a shop charges.

I shared an example of a customer using Google's AI-generated search results to compare parts prices. The problem is that those results don't necessarily reflect what a professional repair shop needs to charge to cover its costs and make a reasonable profit.

And then there's the way parts pricing matrices work.

Many matrices apply a lower markup percentage as the cost of a part increases. So, as your average parts cost goes up, your overall gross profit percentage can start coming down unless you adjust your pricing strategy.

That doesn't mean you should immediately raise every price. But you do need to understand what's happening to your margins.

Your Labor-to-Parts Sales Mix Matters, Too

Lucas's shop was also generating a relatively high percentage of its sales from parts rather than labor.

Because labor typically carries a higher gross profit percentage than parts, a parts-heavy sales mix can pull down your overall gross profit margin.

We talked about working toward a mix of roughly 55% labor sales and 45% parts sales. That was a target for Lucas's shop, not a rule every shop needs to follow.

Lucas had already implemented a labor matrix that increased the effective labor rate on longer jobs, which helped improve his labor sales. We also discussed opportunities to bring more appropriate maintenance work into the shop.

The goal is to understand how your pricing and service mix affect the gross profit dollars you're generating.

If you haven't reviewed your parts pricing recently, our Parts Pricing Matrix can help you evaluate whether your pricing tiers support the margins you're trying to achieve.

4. Your P&L Says You're Profitable. Your Bank Account Disagrees.

This is one of those things that can drive a shop owner crazy.

You look at your P&L, and it says you made money. Then you look at your bank account and wonder where it all went.

Net income and cash flow aren't the same thing.

Lucas owns his shop's real estate and other assets through the operating company. Instead of paying rent to a separate landlord, the business makes loan payments.

The interest portion of those payments shows up as an expense on the P&L.

The principal portion doesn't. It reduces the loan balance on the balance sheet.

But the money still leaves the bank account.

During our conversation, we worked through an example using approximately $154,000 in monthly sales.

At a 60% gross profit margin, that would generate about $92,400 in gross profit.

Subtract approximately $85,000 in operating expenses, and you've got around $7,400 in net income.

Not great, but profitable.

Except Lucas still had principal payments to make.

Once we factored in the principal portion of his occupancy-related debt, there was only a few thousand dollars left. And he still had other debt obligations to cover.

Suddenly, that profitable month doesn't look so comfortable.

That's why I don't want shop owners making decisions based solely on what the bottom line of the P&L says.

Your P&L tells you something important about profitability. Your balance sheet and cash flow tell you things the P&L can't.

You need all of them to understand what's happening in your business.

5. What Happens When Your Marketing Works Better Than Your Shop Can Handle?

Here's a problem you might not expect.

Lucas was working with Shop Marketing Pros, and their marketing was doing its job. The campaigns were bringing in customers, and the shop had improved its ability to turn incoming calls into appointments.

But the shop was having trouble keeping up with the additional work. But as more vehicles came in, the shop started getting overloaded.

The cars weren't moving through the repair process quickly enough. The work was piling up, and the business wasn't collecting the money fast enough to keep pace.

At that point, spending more on advertising wasn't necessarily helping.

It was putting additional pressure on an operation that was already struggling.

And there's another cost to consider.

What happens when a new customer finds your shop, schedules an appointment, and then has a poor experience because you can't get the work done in a reasonable amount of time?

You might lose that customer for good.

Lucas decided to temporarily reduce his advertising spend while working on the operational issues.

That made sense for his situation.

But I wouldn't take that as a blanket recommendation to cut marketing whenever you're busy.

Your shop's location, customer base, and available capacity all matter.

Lucas operates in a market where he can't count on a steady stream of drive-by traffic. He needs marketing to bring customers in.

The question is how much demand his shop can handle effectively.

There's no benefit in paying to bring in more work if you can't get it completed and collected.

How Much Revenue Does Your Auto Repair Shop Actually Need?

Once you understand your expenses, debt obligations, and what you want to take home as an owner, you can work backward to figure out what your shop needs to produce.

Lucas and I calculated a monthly gross profit target of approximately $109,000 based on his operating expenses and other cash needs.

At his current gross profit margin of 53%, here's what that means for monthly sales and car count.

That's about 49 vehicles per week.

Now, what happens if we improve gross profit from 53% to 56%?

Same gross profit target, but approximately $11,000 less in monthly sales required.

At a $970 average repair order, that's 12 fewer completed repair orders each month, assuming the shop maintains the higher margin.

And that's before considering the potential savings from reducing unnecessary warranty expenses.

Instead of assuming Lucas needs more sales, we can identify which changes will actually help him reach his financial goals. Improving gross profit, reducing unnecessary expenses, and getting vehicles through the shop faster can all contribute.

The question is which changes will have the greatest impact.

So, What Do You Fix First?

By the end of our conversation, Lucas and I had identified three opportunities to focus on over the next three months.

1. Get warranty expenses under control. Tighten up warranty practices, address quality control issues, and work toward reducing warranty expenses from approximately $15,000 to 1.5% of revenue, or about $3,000 per month under our model.
2. Improve the labor-to-parts sales mix. Look for opportunities to generate more labor revenue through appropriate maintenance services and continue evaluating the shop's labor matrix.
3. Improve parts gross profit. Review pricing to see whether we can gain even a percentage point without creating unnecessary pushback at the front counter.

Now we have a plan and numbers we can track to see whether those changes are actually improving the shop's profitability.

The Money You Need Might Already Be in Your Shop

I appreciate Lucas's willingness to share his numbers. It's one thing to know your shop isn't performing the way you want. It's another to dig into the financials and find out why.

Lucas came into the conversation knowing his shop wasn't producing the financial results he wanted. By the end, we had a much clearer understanding of why and a plan for what to do about it.

And that's really what I want shop owners to understand.

Sometimes you do need more customers. Sometimes you need to raise prices or make changes to your staffing.

But sometimes the money you're looking for is already sitting in your parking lot, getting eaten up by unnecessary warranty work, or disappearing a little at a time through shrinking margins.

Before you chase more revenue, make sure you're getting the profit and cash you should from the work you're already doing.

That's where I'd start.

Hear the Full Conversation

Watch the full conversation or listen to Under the Hood CPA wherever you get your podcasts.

Know Where Your Shop's Money Is Going

At Kaizen CPAs + Advisors, we work with independent auto repair shop owners to understand their numbers and turn that information into better business decisions.

If your shop is bringing in revenue but the profit and cash aren't where they should be, let's figure out what's happening.