Inside the fenders you could use a little paint thinner on a rag or spray some Gunk engine cleaner on the spots at the local car wash and let it sit for a few seconds and then pressure wash the yellow off. Depending on what happens inside the fenderwells you can spray a little Krylon flat black and take care of the inner wells.
On the outside I would try some bug and tar remover and see if that loosens the yellow up. It will not hurt the factory paint. If this does not work try some 3M brand polish and some elbow grease. The polish should remove the yellow and then you can rewax after the yellow is gone. You might even try the pressure washer at the car wash with no chemicals at all. If your car has a good wax job the yellow paint may loosen up and spray right off.
On the outside I would try some bug and tar remover and see if that loosens the yellow up. It will not hurt the factory paint. If this does not work try some 3M brand polish and some elbow grease. The polish should remove the yellow and then you can rewax after the yellow is gone. You might even try the pressure washer at the car wash with no chemicals at all. If your car has a good wax job the yellow paint may loosen up and spray right off.
