best way I know of...
Propane torch, and a metal scraper..
Warm up the undercoating (don't catch it on fire)
Then scrape it off.
Only work about a 6"-10" patch at a time..
P.I.T.A. but works really good, and takes about 3 hours to do the complete underside of a car
"Bye" Bye" Riceboy
(Ex-wife fore sale... take over payments)