Re: under coating for the salt
I too purchased an AZ FJ. It was a 2010 that still had grease pencil markings on the frame after 5 years.
I decided to try Fluid Film. It is basically inert lanolin-based grease that simply isolates the metal from the oxygen that causes rust. I have a compressor so I bought a spray kit and buy FF by the gallon (Woolwax is another similar product BTW). I spray it once a year in the fall and touch up with aerosol cans. The only stuff that needs touch up is a few leading edges underneath that get sandblasted in normal use, like the front edge of the lower control arms.
After 4 years I have next to no rust underneath and am pleased with the results and will keep on doing it.
Steve in MN, sponsored by Blue Sun Corporation
2010 FJ, now with exciting grill and shifter knob mods
"Speed has never killed anyone. Suddenly becoming stationary, that's what gets you." - Jeremy Clarkson