After some heavy sanding with 60 grit paper to remove the clearcoat and rough up the painted surface areas, I applied a Flexible Polyester Putty from SEM products:
I used 60 grit paper to knock down and shape the filler material, and finished with 150 grit paper. I also touched up all the nicks and scratches that were already on the bumper from road rash and crap. I'll hit it with some 220 grit real quick before its primed.
