How I Spot Bad Paint and Panel Gaps When I’m Looking at a Used Car
The main thing to look for when inspecting a car's body is consistency. Paint and panel gaps should be uniform.
Buying a used car is probably one of the more treacherous activities we undertake with some regularity. That’s why plenty of shoppers go for a pre-purchase inspection, or PPI, to track down mechanical ailments before they buy. But one area that sometimes gets overlooked is a car’s body itself. I’ve taken a cursory look at cars in the past myself, said “yep it’s pretty much the same color” and called it a day, but you may want to go much further. Finding hidden repairs or damage can be hard but it’s not impossible.
I’ll preface by saying that buying a car that’s been crashed and repaired isn’t necessarily the worst idea, as long as the price is right and you know what you’re getting into. At a minimum, understand that repaired cars lose some resale value, so build that into your buying price and your total ownership calculation when you think about reselling it. But even if you never plan on selling whatever car you’re about to buy, if it was damaged, you’ll want to be able to assess how well it was repaired for your own peace of mind. Or maybe you don’t want a previously repaired car at all, in which case you can think about some of my tips here and know what to walk away from if something looks off.
Repairing paint, metal, and plastic is time-consuming and difficult. And while there are plenty of good body shops that do excellent work, an unfortunate truth is that the industry doesn’t always reward artistry or care and sometimes corners are cut. So you’ll want to be careful when you’re looking at a used car that might have been in an accident at some point, even if it looks generally straight and clean in photographs.
Doing some research with automotive background check tools like Carfax or AutoCheck can tip you off to whether or not a car’s had bodywork done, but not all collisions are reported anywhere so trust your eyes and trust your instincts.
When I’m scrutinizing a car I might buy, like most people, I usually start with the photos in the car listing. I’m not looking for any shoddy paint finish work, you won’t be able to see that in pictures. But what you often can see is uneven, inconsistent, or large panel gaps across the vehicle.
“Panel gap” is a term that gets dropped a lot in automotive writing, and while it is sort of self-defining we’ll offer some clarification for those who’d appreciate it. Panel gap simply refers to the space between the big planes of metal that form the car’s body. That thin line between the doors, or between the hood and the fender, those are panel gaps.
Some cars (usually cheaper ones) have big panel gaps from the factory, so don’t concern yourself too much with the actual size of the gap, but the consistency of the gap or gaps. That will give you a good clue as to if the car’s been re-assembled at some point in its life.
For example, looking across the driver’s side of my 2010 Volkswagen GTI, you can see that my door gaps are pretty egregious. The driver’s front door to rear door gap is huge and tapers wider towards the bottom while the rear door to fender gap is smaller. This could be because the panel was removed and re-installed inexpertly, or the mounting points shifted from a collision and weren’t tweaked back into place. It’s a surefire sign of something going on. I spotted that in the original ad for my car, but the price was right for some minor stuff so it wasn’t a dealbreaker for me.
Let’s take that panel gap observation and leverage it into some closer investigation. Once I had a chance to see the car in broad daylight (important!), I immediately started taking a good look at the driver’s side of the car. To get a good feel for the panel gaps, I ran my finger along the gaps feeling for the width of the gap but also if the panels are level with each other. Depending on how well screwed-together your car is from the factory, panels with uneven depth are not uncommon even on totally original cars. While I look out for it, I’m generally more concerned by very wide gaps or panels that sit excessively proud of one another. Excessive usually means visible from five feet, and it’s usually most common on front bumper fitment after front-end crashes.
Next, we have to check for bad paintwork. This one can be really tough to see, which is good and bad. If you can’t tell anything, then it’s likely that good paintwork was done but some bad panel fitting happened, whether DIY or professional.
Bad or even semi-bad paintwork sometimes won’t be readily visible either, though. Often, the color matches up decently but not perfectly. This can be masked with paint blending, so you’ll have to look closely and broadly at the car to spot any subtle changes in color shade. Ideally, try to see the car you’re looking at in a few different lights — if you’re out in broad daylight, even just re-orienting the way the car’s parked in relation to the sun could accomplish that for you. Sometimes paint will be very obviously different from panel to panel, sometimes it will gradually change shade over the length of any side of the car. For example, it’s easiest to tell that my driver’s rear quarter panel has been repainted because the color changes from front to back and side to side on the rear. One of the most obvious signs of bad paint application is at the edge of panels where the paint collects and drips down, creating a thick edge of paint, most common on repainted hoods. You can usually feel the extra thickness with your fingers, it feels like a rounded lip.
The paintwork also includes the paint finish, like clear coat and polishing. Repainted panels can look duller relative to the factory paint, or have different finishing detail like orange peel. Using the ever-present example of my GTI, we can see that the re-done paint is much duller and doesn’t have much of a gloss to it. Compared to the door next to the rear quarter, the quarter doesn’t have as much mirror effect as the nice factory clear coat on the door. Big red flag! At least, if you care about some “honest” bodywork.
Sometimes, you’ll even find what look like scratches or gashes within the paint. That is from poor prep work, specifically sanding. Flaking paint is a sign of bad prep work, too.
Now, if the car looks totally straight and clean, even with an accident history, the likelihood is that the bodywork was done by a great shop. The only way to find damage, in that case, would be a paint depth gauge. For me, If the car looks good and is repaired with genuine panels, I don’t really care. I can’t drive paint. But if you do want a complete history of the vehicle, documented or not, a good paint gauge will tell you more about the car.
Operative word: Good. A cheap Amazon paint gauge will be too inaccurate for useful readings, with some having margins of errors exceeding 0.05 mm. So if you really care enough about paint quality to get a paint gauge, you might as well spring for the most accurate one possible. Around $100 should get you one that is accurate enough for the typical DIYer to use for inspection, while higher-end ones are more for professional use.
They’re simple enough to use: turn it on, calibrate it on an uncoated metal surface, and start applying it to various panels on the car. The thickness of the paint itself doesn’t matter so much as the variation in thickness across metal panels — consistency is good. If the thickness of the paint across the entire metal part of the car is more or less the same, you can be confident that it has never been crashed or repaired. If there’s variation from panel to panel, closer investigation is warranted. Some gauges won’t measure plastics or fiberglass, so make sure to check what your gauge can detect. Generally, they’re good for metal surfaces.
Next time you look at a car, take my tips with you in your back pocket. It may just save you from buying something that was misrepresented, especially if the seller considers it a big selling point. I’m training myself to care more about bodywork and paint because of my history with buying some aggressively honest cars. I want to own something nice these days.
Got any extra tips or tricks? I’d be happy to hear it in the comments.