Last winter I spent hours digging out accumulated dirt from the fender wells on my car. It can get into crevices a water hose would never find. The perfect scenario for onset of corrosion.
I think the newer cars (993, 996) have liners in the wheel wells. A great idea, but too late for the SC's, Carreras, and early 911's.
------------------
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website