Thanks for the advice blue, just two more quick follow up questions:

1.) Would you wet sand/polish just the affected area's or should I do the entire headlight? I'm worried that if I do just the areas affected by the time im done just those areas will look different from the rest of the headlight.
2.) If a claybar is the only way to get the tar off I will purchase one but I don't see how rubbing clay on a rock hard piece of tar will get it off - excuse my ignorance I just don't have any experiance with claybars.

My windshield has some scuffs/scratches on it so I think I will practice on it first with my kit. Perhaps I will take pictures as I go along and write up a DIY.

 

Haha yea i hear that all the time. Tar on cars sucks claybar takes a while but works flawless. Try it you'll be very surprised then ull do the whole car with it. After you clay it will feel like a babys ***. Try a small scratch first wet sand then buff it if u like it do the whole thing if it didnt work u didnt **** up the whole thing lol