Hi Rob, that radiator is at least 3 years old. Probably road salt like you mentioned. A light dusting of snow over here makes everyone panic. someone mentions snow and the plow comes down the block. Mamby pambies.
I figured one of those racing style radiators but you know what,....I dont want to spend a bundle. I guess I'll just go back to the autoparts store and buy a regular one. I just wondered if one brand name is better than another. And , which it might be.

Short story: I work in manholes in Brooklyn, once we had a job at a location where they stored road salt nearby. When we opened this rarely opened hole, the aluminum (and other mix of metal) splice case , about 24" x5" diameter, was in a beautiful silvery pile directly under the case, on the floor under some water. The phone cables were just hanging there, still working mind you. We realized the rain would wash the road salt right into the manhole and it disolved the metal case.