Water stains in rear window
I recently purchased a 2008 535xi (great car!), all around in great condition. One issue - in the lower corner of the passenger side back window, there appears to be some dried water / condensation, about the size of a frisbee. The problem is, it appears to be between the glass (do the back windows have 2 panes of glass?). I've cleaned the outside and inside, and I can tell that the stain is not being touched. I've tried the defroster too.. but it's already dry.
You can't really see it in the day, however, at night with lights from other cars behind you, it looks like that part of the window needs a good cleaning.
I'm not sure how this could have happened (I thought maybe a leak, but it's on the bottom... not leaking from the top), nor really what the stain is, but I have 3000 miles left under the original factory warranty - do you think the dealer would clean it (if possible), or at best, replace the back window at no charge?