I just had some fender mods done (had a fender lip ground away to accomodate new wheels--rolling the lip caused the repainted skin to break) and wanted to know the pros and cons of rubber undercoating. The product I'm interested in trying in Westley's, and it is water-based. My hope is to better seal the painted grind job, and generally add to the sound proofing of the car. Any BTDT's??? TIA, Brian