We're not in the rust belt, and my '92 spent most of it's life in the SF Bay Area. But after being up here in the snow for over 6 years there is now a little rust. For the 2 years I was commuting over the mountain, it saw quite a bit of moisture and some salt (though they don't use much). But this is just tiny amounts of rust, compared to what most 20+ year old 4runners would have.

What do you guys do to prevent or minimize rust under the 4runner? I was just painting our house gas lines with grey "rust stop" paint from Ace, then some things on one of the snowblowers, and decided to touch up a couple things on the truck too.

I'll go back in a few days with black on the truck, and might crawl under some more to get more places. Unlike most of the country, we have warmer temps and much less snow than normal so far.

I use POR-15. However, you have to put a top coat over it to make it work. I brushed it on my frame without a top coat and after last winter, I got little rust dots all over where I brushed it on.

That sounds like good stuff, and if I was in a severe rust area I'd consider switching to it. Their site says you shouldn't need a topcoat if it's not exposed to UV light, but in general it always seems like a good idea to put a second coat. POR-15 Technical Information