Since its out of warranty my fix would be cut out a 8x8" square to remove the bad metal, dry throughly (if damp) and screw/seal up a access cover over the spot/paint to match. I wouldnt buy a new unit if just cosmetic damage but thats just me.
*Currently trailer-less but shopping
07' GMC Envoy w/ P2 controller (current TV)
88' Chevy K5 Blazer (soon-to-be TV)
74' VW Superbeetle (1303)