What is on my paint?

Bought the wife a new (to us) 2013 a couple of weeks ago. Metallic white.

Car looks just fine. Shiny clearcoat, does not even have any noticeable swirls.

Washed it this weekend, water beads a bit on the sides, but on top surfaces, water stays on as a sheet. I decided that I would wax it, but I figured I should use 3M Hand Glaze to polish it before waxing.

Paint surface feels like 1000 grit sandpaper. Amazing since it looks so shiny.

I first noticed roughness on the windshield when I cleaned that the other evening. The glass looks clear but is surprisingly rough when you wipe a paper towel over it.

I hoped that the 3M Hand Glaze might take the roughness off the paint, but it has no effect. Also, I found that I cannot use microfiber cloth to polish the hand glaze. A microfiber cloth will not slide across this surface. The cloth just wads under my hand like a sheet of rubber. I had to use an old cotton T-shirt to polish off the Hand Glaze.

Could this stuff be some sort of spray-on wax from a car wash? Sap from some plant? (Northern California car) The fact that it is far more pronounced on top surfaces than sides pulls my suspicion more toward plant-based culprits. I don’t think that it is water spots because those would be visible and would not look shiny. The car has a few water spots on the passenger side, probably from a lawn sprinkler. Those spots look dull.

How to remove without marking or thinning the clearcoat? Any chance this stuff is attacking the clearcoat?


Been parking under trees? some trees release sap in a fine mist that hardens in the sun and becomes very difficult to get off. Sometimes I’ve had to get a gasoline-soaked rag and rub the sap off, then immediately wash and wax the car. It’s a huge pain, but better than using abrasives.

I’m guessing the previous owner either lived in an area with acid rain, or sand storms, or spent a lot of time on dirt roads, probably following dump trucks.

Once the surface is etched, you can polish the surface to improve it but you’ll be removing material by doing so. I’d recommend having a reputable paint or body shop evaluate the finish and get their professional opinion and recommendation.

Sincere best.

Your comment about “shiny but rough;” “mostly on top” makes me think tree sap is more reasonable. I would try various solvents, perhaps testing them first on an inconspicuous spot for safety. Goo Gone, gasoline…??? If it works, wax afterward.

I’d try a clay bar treatment, see if it makes any difference. If not, I’d do as TSMB recommends, find a pro to diagnose it.

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You might also try bug and tar remover. It works well on tree sap.

I think you should take it to a detailer who can machine polish and wax the surface. A glaze is not a polish, only a filler. If you don’t want to hire someone you need to start with a good washing with a good car wash solution, then use the clay bar to remove contaminants, then a polish (preferably machine) like Meguiars swirl remover or similar, then if you want to use glaze ok, then wax. A detailer though will at least be able to tell you what is in on the paint now.

I also vote for trying bug and tar remover to see if that helps. If it does, I’d use a clay bar after that to smooth things out.

Just return to the place you bought the vehicle and they most likely have their own detail shop and let them look at it. The worst is they recommend a good detail shop if they won’t solve your problem. You just bought a 2 year old car why pour gasoline or some substance that will make it look worse when detailers will have to stand behind their work.

Clay bar and then wax it. Clay bar should get off all the impurities and wax will seal it. A car that has not been waxed in a long time will feel exactly as you describe.

It’s probably “rail dust”.


Just follow the instructions.


@Manolito, you seem like a discriminating buyer. I’m sure you inspected the paint well before you bought the car. Did you buy it from a dealer? If so, take it back and ask them to remove the stuff. They must have cleaned the car before putting it on the lot and have to know about the problem. If a dealer is involved, they might claim ignorance, but that clearly couldn’t be the case. Remember that consumers are considered “uneducated” since they Rent necessarily experts on things like this. But the dealer is supposed to be an expert in everything concerning the stock on his lot. If this was a private sale, you can try to find out what the previous owner knows about it and then take it to a detailed. A few hundred bucks to clear this up is better than living with it.

Glass is impervious to just about any chemical you put on it. You might try cleaning a small area with a strong solvent. Rinse with a lot of water immediTely to bet it off fast so that it doesn’t damage the paint, metal trim, or rubber. If that doesn’t work, you will probably have to buff it off. Unless you are ace with a buffer, you should probably get a detailed involved.

A shop probably clay bar and buff it

Probably some kind of tree sap, internet has mixed responses on claybar, lived in CA and had eucliptipys sticky stuff, it went away eventually, as I am a maybe every couple of years I wax my old car. Duco and prepsol seem to get some reccomendations, but other stuff like wd40 and alcohol does also. I would be leery of internet suggestions, and take it to a trusted detailer.

If it also appears to be on the glass, I might be inclined to see if a brand new single edged razor blade will take it off. Be careful, use at steep angle and go slow to avoid scratching glass. I’ve razor bladed my windows before when they got a lot of sap on them. But this may differentiate between something deposited on the glass versus pits from driving…

You can’t harm the paint with mineral spirits. That’s about the only solvent I will use on my cars. I just got intimate with the building wall here at work and used mineral spirits to remove all of the transferred paint without affecting the factory paint. It works on any sap I have had as well. Try that in an inconspicuous area and see if the paint goes from rough to smooth…

Once again the CarTalk Community comes through with a wealth of helpful suggestions! Thank you all!

As for inspecting the car before I bought it, I looked it over carefully from one end to the other, looking for panels that did not fit squarely, door dings, scratches and swirls, but it never occurred to me to run my hand over a shiny surface until I washed it.

In addition to the cleaners mentioned here, one product that I looked at was Chemical Guys Citrus Wash. Anyone had good or bad experience with that?

I got the car from a reputable BMW dealer who sent it out to a detailer. The detailer had to have noticed this stuff, but probably gets paid a flat rate per car and chose to ignore it since the car looked good.

BTW, for those interested - the car is a 2013 BMW 328 convertible. It has a folding (aka “origami”) hard top. I lubed all the rubber seals with Krytox and the moving parts with Wurth HHS-K last weekend. Between the three-piece top and the trunk lid that opens both ways (from the front and from the back) that top is unbelievably complex. If the car is ever wrecked, it will be all over because there will be no way to get everything straight enough to work smoothly and not leak. I told the wife that this is a once-in-a-lifetime fun car, not a practical car. She is really enjoying it. Her high school students call it her Transformer car.

You’re right about the complex top on that BMW. Friend had one, got bumped in the trunk in a parking lot (5 mph or less), they totaled the car. One year old…OUCH!

Cool car! I guess you discussed this with the dealer. What did they say about it? It seems to me they should fix it for you since they sold it that way.

Figured out what it was. They retouched several spots before we picked up the car. The roughness is clearcoat overspray. It is slowly wearing off with repeated washings and it is not visible, so I live with it.

I figured it out when I resprayed some clearcoat on another car and failed to mask off every bit of the car. Ended up with the same invisible roughness on every bit of glass and body that was not covered.

Thanks for the follow-up. Did the overspray happen at the factory then, where the car was manufactured?