Used to work at a ford dealer that stopped undercoating cause it cracks and moisture gets under it, course people kept vehicles longer then. LOL gotta run my old mouth here. Knew a guy that did undercoat then,his lift, old forklift, his stability was 2 old 55 gallon drums, placed under the rear axle. he steam cleaned the bottom, cranked up his air pressure and sprayed. Oh ya he chocked the front wheels rofl