QX56 Corrosion on Roof Rack and Window Sills

[T-Indy]

We just purchased a 2008 QX56 with approximately 44,000 miles. We didn't realize their was a corrosion issue on several of the plastic/rubber trim pieces. The roof rack and window sill both have rough corroded surfaces. I saw a mention in a post from several years ago about similar issues with roof racks in Florida. We are in Indiana, but the vehicle was originally sold in FL. Has anyone else experienced this issue or heard anything about it?
We took it to the dealership thinking it could be a warranty issue, but they say it is "environmental damage" from some previous exposure and not a defect. Would appreciate any input.
Thank you!

[Socaldiablo]

Well, most all vehicles are exposure to environmental damage so it sounds like they were trying to say that it's just something that happens ...in a fancy way. The black rubber seals around the windows on my 04' QX56 have formed a rough surface from exposure to the elements but it's not something that I really care about. It's not that obvious. When you say roof rack, though, I'm a bit confused as that is not rubber. If you are referring to the actual roof rack, that might be something else. It could be tree sap that has since been "baked" into the paint on the rack. An auto detailer can remove this. Can you post a photo of the rough surfaces? If you're really concerned with the window seals, you could always replace these.