Last year, i had my 4runner parked at the boat launch and someone side swiped me with their trailer. It was a silver vehicle and was a white trailer. When I first saw it looked terrible. Luckily, it didn't dent it, but it did leave a streak on the front fender about 2 inch by 8 inches of white paint. I come from a back ground of painting and buffing, so I had a few things on hand. First of all I say this cautiously, because it can get you into trouble. I washed the vehicle to get rid of excess dirt that can act as an abrasive. This is the part I caution you on, I took a soft clean cloth with a small amount of lacquer thinner and in a spot that couldn't be seen made sure the lacquer thinner didn't affect the finish.
Once I saw it didn't affect the finish, I tried a small amount on a clean cloth. It immediately took the white paint off and I didn't leave it on more than 30 seconds. I immediately washed the spot with dawn dish soap to remove any lacquer thinner. This took the white paint off, but I was still left with a slight scratching. The next step was to use 1500, 2000-3000 wet sand. I then started with buffing material and worked back to polishing pad/ polish. I was able to get this plenty acceptable.
I am just telling you how I did this, it is very easy to mess this up and make it worse if you don't know what you are doing. I would worry about 2 things that could go wrong with this repair. Don't use a solvent that affects the finish and get it off immediately. Second, depending on the color white and silver are pretty forgiving, black not so much, polishing is going to leave scratches. You need to get these out by using progressively finer material and pads. I will guarantee if you are working with a black vehicle, you will definitely see the scratches.