I haven't used that particular primer, but I can tell you what most of the paint manufacturers will tell you...strip the car to bare metal, do your "heavy" metal bumping, lay down 2 coats of epoxy primer, do your "medium" fill work, lay down a high-build primer, block sand and use "fine" putties, then throw a sealer over that immediately before painting. In short, you want to get the bare metal covered to keep rust from forming. You want to use an epoxy primer for this as it is NOT porous...it's also not meant to be sanded (other than scuffing prior to laying down a different type of primer or body filler). If you have had the car blasted or used a mechanical means of stripping, there should be enough texture on the bare metal for the primer to bite into. If not, you may have to prep the car with a DA with 80 grit.
does this help?