Oil pan eroded! Is this unusual?? on 2004 Jeep Grand Cherokee

Noticed an oil spot on my garage floor where i park my 2004 GC-"Limited" (8 cylinder). Barley 80,000 miles & no off road stuff.
Took into to the dealer as it was due for an oil change & filter. (I thought maybe the oil drain plug got "stripped")
Service Dept said the oil pan was eroded. ~$800.00 to replace it.
I am wondering IF the Wisconsin winters with snow & salty roads & car washes that advertise "underbody flushing" caused the oil pan to erode?

Asked by for the 2004 Jeep Grand Cherokee
1 answer
Wisconsin salt will do that. Once the undercoating is compromised, vehicles in the northern states with a lot of salt on the roads during winter, will accelerate rust. So, this is definetly possible. Here's a DIY procedure if you wish : http://www.ehow.com/how_4508569_replace-oil-pan-gasket-jeep.html