Clay works well, any fine cut compound will work with a buffer machine.

I can also vouch for WD-40 on road tar and oil. Dissolves it right off.

My neighbor has a white Ford Crown Vic, and he ran over some green paint, and got it all over the lower part of one side of the vehicle.

It was quite stubborn and we ended up coloring sanding the green paint off with 1500 grit wet sand paper. Took it right off and restored his paint at the same time.

We followed up with 2000 grit, then fine cut compound, then polish, and hand rubbed Meguiar's Gold Class Liquid Paste Wax. Car looke show room new.

Don't be afraid to use wet sand paper. A regular application won't ruin your paint. If you're afraid, start with 2000 grit and keep it wet.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".