[Pushit2.0]

Clay bar is used for rail dust, tree sap, road tar, slight over spray. I would start with paint thinner (what color is your car and be carful on the plastic, this will take anything off but the clear coat and paint so it will look pasty white untill you buff it, Mistu red has no clear coat so you take paint off when you buff/use paint thinner on a red mitsu) and then try a clay bar (lots of lube, soap/water) then try buffing it out, the razor blade would be a last resort item.

~John