I'd be more concerned with body corrosion (yours) than corrosion of metal bodies....../QUOTE
For Sure! But how does one prevent that. Aint no fun with corroded degerating body parts. Puts a real damper on doing all the neat stuff.


Now back to rust:
On the truck and trailer I've gone over the undersides with sand blaster/needle scaler/wire brush, then applied a solution of phosphoric acid, did the mechanical clean again, more phosphoric acid followed by a rust inhibitor paint sprayed on. The last home step involves using the sandblaster gun spraying on a 50/50 mixture of roofing gunk and diesel. That is followed by Crown Coat to get the closed portions like doors.
Not as much work as it sounds like but it is rather dirty. So far it has worked well. Trucks 15 years old.
The cars have received a standard undercoat like Ziebart which also has a solution sprayed into the doors etc. Just had the lexus done.