My dodge has never seen a heated garage in its life.

The worst spots for rust are where the foam sealant is between body panels, or where dirt gets held captive. Not much you can do there.

I actually bought a case of Fluid Film last year after hearing all the good about it. I applied it to two trucks before last winter, and by this winter it was 90% washed off. I would say it lasted about twice as long as a good oil coating, but was a bit disappointed.

Only thing I've seen that really holds up is a mixture of mill grease, diesel, and cosmoline that is sprayed/brushed onto things. Local guy does something similar, and I've been experimenting myself with different mixtures. It's best to apply it to clean metal before the rust starts, and it makes an unholy mess whenever you have to work on something, but it works. It stays tacky and will "bleed" back into areas that get scratched or wiped clean.