Overspray clay does work on just about any overspray. But if you have traffic paint, most states have now switched to latex, which isn't too hard to remove. If it's oil based, it can be a bit more troublesome.
Worst is the hot plastic "paint" they use with glass beads for reflection. If you get that on a finish, it's very tuff to remove without a solvent to get it off. You can use heat, as long as there is no glass beads used as wiping that off is like wiping a finish with 400grit paper.
Latex paints are easy to tell by feel and the way they peel off.
Most tar removers are mineral based. Some are Naptha and some other spirits.
Always go less agressive first and work up.
Deanski