2010V6Stang

What exactly will start to happen in a few years? Just rust on the underside? I constantly wax and winterize my stang since I have to drive it in the winter, I just hope thats enough to keep the outisde good. My car was so smooth from all the wax lol.

Nuke

Rust from salt and other chemicals, besides rusting the undercarriage FASTER (the undercarriage will develop surface rust normally), rust will begin behind panels and in crevices that you either can't get to with pressure washing or where pressure washing drives the salt deeper into the crevice. What often happens is you'll see a paint bubble somewhere due to rust forming on the metal behind the paint. All the waxing in the world won't stop that kind of rust.

In a perfect world, don't expose the car to salt, period. But we all can't do that so the best you can do is keep it washed & waxed and flush the undercarriage the best you can and as often as you can.