I drive a 2016 Tundra in Michigan and its got 250k miles on it with zero rust. Lots of car washes with underbody in the winter because we use salt on our roads. Also have a 2012 4Runner with 140k miles, same thing..no rust and clean. Just take good care of them and you shouldn't have issues. The other option which I have not done is to have the full underbody coated at Zeibart, my dad used to do that to his early Toyotas that were know for rust issues and it worked very well.