2010 Mariner with only 48,000 miles on it. I have rust on back wheel wells.

I have just under 70,000 miles and have the same problem - rust on both rear wheel wells. The rest of the car is fine (2010 Mercury Mariner) and in great condition. I took it into the repair shop and was told it would cost $2000 each to replace the quarter panels. They also said this is a common problem for the Mariners, Escapes and smaller SUV's. I am not happy. :(

The salt from snow and ice removal has caused this issue. Not sure how well the metal has been sealed from the factory, or maybe this car was to be sent to Arizona where there is no such issue for corrosion.