Removing undercoating?
That's Master Series Silver. It got a coat of the shiny chassis black after that. Two coats of each actually. Prep was a lot of work...scrub, wash, rinse...multiple times. Scrap, scrub...rinse, spray with degreaser...all kinds of stuff. Took probably 80 hours under the car in total to clean off all the oil spray, undercoating, dirt, etc. and apply the 4 coats of paint...all on my back looking up with a face shield and/or goggles.
I like the Master Series but on my daily driver van it's bleeding through, perhaps because it sees salt and heavy weather...not sure. I sure hope some rust doesn't bleed through on the Deviant project, that would suck.