[dsraven]

you know what I do, come the filler stage, is apply, sand, etc. then, before i shoot primer, i place a shop light at one end of the project and then wipe the part down with a really wet rag of wax and grease remover. then stand at the end opposite the shop light and check the reflections in the still gleaming wet surface. it's a great "tell" to see if there are low spots, wavy spots, ripples etc. then apply more filler as required or, if it's all down to the small stuff, apply the high build and use the guide coat theory.