Lots of tar removal products at the auto parts stores...I can't remember brand names, but I've used many and not had problems with any of them.
Back in the day, I used kerosene...had a summer job at the IDOT motorpool, and employees drove the state vehicles through all sorts of road construction, with tar being the most prevalent.
Kerosene took a bit more elbow grease than the products on the store shelves do today. Probably less harmful to your paintwork too.
Expect to rewax your car after getting the tar off, of course.
