Summary: When detailing a car exterior, remove road tar or grease by using a solvent-based cleaner. Remove unwanted road tar with tips from the owner of a car detail shop in this free video on exterior car details.
"Hi, it's Dow here at the Firehouse Detail Shop. Today, we're detailing the exterior of a car, and teaching you how to do it like a pro. We're moving on to the removal of grease or road tar. You might also find an occasional paint that gets on here from striping or things. Really, the only way to get this off efficiently is to use a solvent-based cleaner. The the challenge with the solvent based cleaner is A, it's flammable; B, it's hard on your skin; it's dangerous if it gets in your eyes, so please make sure you have a safety precautions that we talked about; rubber gloves, safety glasses, and keep your skin protected. I've got grease on this car. It might, it could be grease, it could be road tar, so what I'm going to do is go in with this solvent and just simply put a nice gentle coat on there and and wipe it off. Not a lot of pressure required, and I get that off. Now if that was tar I'd do it the same way. The challenge here when I use a solvent-based cleaner is that it also strips all the protective coatings. Now, later on, we're going to be putting wax over the entire car, and teaching you how to do that, so we're okay. But if you're doing spot cleaning, don't forget that you have got to reapply some wax and polish,or protectant back on the, on the paint to protect it. So I'd move across this panel, again, applying it and just removing it gently as I go across until I've got all the tar or paint. One of the most difficult things for us is the paint; that yellow paint that comes off the striping. It's got a a catalyst in it that hardens fast, so you do want to try to get that off as soon as it gets on. The longer it stays off on the car the more difficult it is to get off. And road tar should come off in a breeze when you have the right solvent-based cleaner."
eHow Article: Car Detailing: Tar