have a new 2014 Terrain (4k miles now) and underside of exhaust system is rusting very heavy. What should the dealer do?

I took delivery of my 2014 Terrain in September in So. Cal. and all the exterior chrome had rust pits, even around ALL the windows and doors. GMC replaced all the rusty pitted parts with new chrome strips. The vehicle is covered with a rust warranty. I wonder if some of the parts used were shipped from a slow boat from China and got exposed to salty sea air. If the dealer does not replace it, and make sure you look for other rust pitted parts, call General Motors Customer Service. This is not the one at the dealership, but from the corporate office it's self. The service provider should give you the number. I have seen them monitor this site and give advice to people. Enjoy your Terrain. I have really enjoyed mine. I saw a guy in Bakersfield Thursday that had a 2011 with 145,000 miles on it. He said it is the best vehicle he has owned. The only thing he had to replace was the shocks.

The picture is my Terrain on our driving trip through the National Parks in Southern Utah last fall. 28.9 mpg for the entire trip. The only problem I have is the birds love to use it as a bombing site.