Somthing to get clear with people who don't work with it too often. Not all fillers are created equal. Bondo is NOT A QUALITY FILLER! It is perhaps the worst. A good filler has to have a base and a hardener (I know i know bondo has that but whatever). For topcoats and imperfections like this it's best to use a fine filer in a skim coat making sure the area is roughed up first.
Definition of a skim coat is just enough to fill the imperfection + a little bit for shrinkage in drying.
For topcoats on cars and guitars if need be I use Evercoat glaze coat.
Glaze Coat
Just search for part #100417
Its is very fine almost a thick paint consistancy
And for those who are doubtful about sticking to paint....I can't speak for bondo because I dont use the junk but I'm assuming from wes that it does not stick.
The back of the Glaze coat container reads "For use over body filler, fiberglass, many plastics including SMC, metal, two component primer surfaces and oem topcoats. I have used it on fender, samik, ibanez and peavey paint with no problems 2yrs + later. And I filled some pretty big holes. Ibanez for example was stripped by some guy with a blowtorch.
Im sorry if im off on a rant but it just floors me when people assume you know jack because you have less posts. There is a world before PG people!