On the older Tundra's it's the frames that rust. My friend had a 2004. They replaced the frame under recall. The body on that truck was mostly rust free.
The newer ones don't seem to suffer from this .
Yeah, that was an issue that only affected the 1st gens. They fixed it on the 2007+ Tundras. Most Tundras tend to be generally rust free, at least the ones that I see around here. I have no clue how they hold up in salty Ontario or Quebec. I CAN tell you that Fords and Rams still rust like crazy around here.
I'm hoping for great things from my Tundra. Since we got the Civic, the Tundra only gets used for long highway trips. Yes, it's usually pulling a trailer, or has a canoe on the rack, but steady state driving pulling a load is still the best thing for that truck. It should last me forever at this rate.