First off, You dont have to sand to bare metal. If you are going to fix the dents you go about fixing them the same way you would any other dent (grind down to metal and lay and sand your mud). If you fix the dents you are going to have to prime the spots you put your mudd, Spray out about foot around the spots and wet sand with like 600. with the rest of the trunklid you can sand with 320 and a red scotchbrite pad. This will be enough so all they have to do is clean it, spray sealer, and paint. this will cut the cost down alot.
