I remember the Ziebart commercials well in Upstate NY. And the rust that people figured out that it caused but some still did it. My grandfather owned and operated a Texaco station and his theory, and it is a good one, is to not wash your vehicle in the winter. Heat is a catalyst for rust and if it stays cold enough then it can't form. Works better where it doesn't above zero F° for weeks at a time. I have a heated garage but park my vehicles outside for that reason there is truth to it.
Had a 67 Mustang and by the mid 70's the floor pan dropped out of the passanger side going down the highway, rusted out. And it was downhill from there. Many claimed the rusting back then was caused by the recycled cheaper Japanese steel that was being imported instead of American steel. There was a lot of action to stop the importation and use of foreign steel
Traditional undercoating makes rust worse.
There are shops that do Fluid Film but it is not widely used. Most people simply don’t keep a car for 10 years.
I climbed under my Taco for 11 years and sprayed FF on the frame. It helped, not perfect and a PITA to do. But not a lot of other options.
My GX picked up in Nov. spent its first 4 years of its life in Texas during winters it was owned by snowbirds from what I can tell. First thing I did when I brought it home was take it to a shop that does NH OU Undercoating. It is basically FF that DuPoint made even better. NH OU started and still is mainly in the NE but are spreading West.
After watching it being done professionally with a high pressure wand I will never do it myself again. He got in places I never ever considered. Almost 5 months later the stuff is still dripping off into my driveway.
If I do get a new GX550 or LC250 first thing I would do is take it to a NH OU Undercoater, they have a wax that they apply but will only do it on new vehicles. The guy that sprayed my GX said mine had less rust on it than some new vehicles that come in with less than 100 miles on it. Obviously moving would help with rust, or lack of.