My vehicles were manufactured late enough to have the rust-fighting technology. Plus, I live in the moisture-challenged "oven" belt, so that probably is also a factor.

The VW however spent most of its life in the Midwest...outdoors 24-7 year 'round. When I took it in for bodywork and paint during the show-car era, most all of the body panels were completely replaced...except the shell, which also needed complete rocker panels and had other bad sections grafted with new sheetmetal.

I bought several bottles of undercoat and an application gun and sprayed nearly three layers of the stuff throughout the undercarriage. Since the car was a looker by then, it really was unnecessary, since I kept it stored winters, and never ventured out in the rain if at all possible.

The car is rust-free as of now (since the work in 1986). The paint is another story...it has sat outside for five years now.

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car