[Arran]

Well for one you can end up with random bits of steel wool getting into the wrong places, I haven't personally but I could see that happening. For another it leaves a scratched up look, especially on the aluminum cans. Some have a rotten habit of doing this to bronze dial escutcheons making them all bright and shiny.
The only detailing I do is to wash the chassis with a TSP solution, and a tooth brush on a hot day, rinsing it thoroughly with hot water, unless the chassis is very rusty. If the chassis is rusty I use rust remover and 0000 steel wool and work at the rust spots with it, then mask off or remove various items, then prime, then paint with brushed nickel metallic spray paint.
Regards
Arran