Fender Inner Panel
Driving through winter snow, ice, and rain means your car or truck is exposed to highly corrosive winter road salt, like it or not. And if you have any trouble guessing which particular area of your vehicle is most subject to rust because of this, just think of the one place where slush builds up the most. The area where you literally have to kick big mounds of it loose. You guessed it - the wheel wells.
However, Fenders are more vulnerable to damage and corrosive elements during a lifetime of use than most other body panels since they're located at the leading edges of your vehicle. These areas are highly subject to a constant beating on the road from stone chips, gravel and other airborne debris you may encounter on your way. These exterior metal panels also often suffer from damage brought by shopping carts and vehicle doors at the parking lot. Dirt, rain, snow, salt and harsh chemicals kicked up by front wheels eventually cause the rust bug to appear and become a voracious eater of their metal surface.