The family car just took a 2000 mile ride on an auto transport. When I
picked it up, I noticed something had splattered all over the auto and ran
down before drying. I have no clue as to what. Looks maybe like tar that
dried. Just maybe, the car was on the lower deck and the one above was
leaking something.

Anyway, today I fired up the 4000 psi 4 gpm 200 degree pressure washer.
(This is just like a hand car wash wand on steroids) After 1/2 hour of
washing, I can see this ain't going to get it.

What should I try from here? Don't want to remove the finish but need some
serious stain removal power.

Karl