I want to keep my car for 7+ years in perfect condition, so I'm thinking about ramping up my new '07 Mustang, sanding off any light rust I find underneath, then painting all exposed metal surfaces with Rustoleum Stops-Rust Clean Metal Primer (7780), then painting over that with Rustoleum Stops-Rust Protective Enamel Gloss Black (7779) ... is this a good idea? TIA

 

i don't see how it could hurt.....

i looked at the underside of a gt500 and there is no rust
proofing at all, just like our gt's....

i plan on driving my stang till it rusts out and falls apart
on the road...

 

You be much better served taking it to a business that specializes in the undercoating business.

 

That's what FORD stands for...Found On Road Dead

 

You'd do best to leave it alone, sounds like you will invite rust, not prevent it. Car rust is a thing of the 70's. Nowadays, withanode underpainting, rust is not something you have to worry about. Additionally, undercoating is more likely to trap moisture and cause rust instead of prevent it. FWIW, I have an '88 mustang that was driven through northeastern winters for much of its life, I never even washed the salt spray off of it, and it is rust free.

 

I'm just gonna do those things that Ford left bare steel. rearend, driveshaft, not underbody panels though, that's all set, do not undercoat. Really, you should be spraying zinc primer and then enamel or urethane with a gun, not brushing on if you can. If no gun, get quality primer from NAPA or autobody supply in aerosol. ...spray topcoat right after primer flashes over.

 

+1 when looking for classic mustangs undercoating is a sign the floor pans are in bad shape. So when I see undercoating I pass.