My car is Montego Blue (Rx7) and I'm getting it repainted Candy Blue with red Pearl. There are some minor dings here and there so I need to bondo/primer. My question is, do I need to sand the whole car (remove all of the old paint), apply bondo to the dings/dents, and then primer the whole car before paint?

Sorry if this is a noob question.

 

Don't need to primer the whole car, only the bodywork. You can use a sealer on the whole car and if it is sprayed right, you won't need to sand it.

 

Thanks. What about deep scratches on the bumper?

 

Try to feather them out and use some high build primer