I just saw this thread after seeing the exact same hard wrinkles on the edges of air conditioner on my 2012 Roo. Mine looks exactly the same as the photo. It is also a Coleman Mach. There does not seem to be any water damage or softness or discoloring.
Now I am curious if others look the same and whether or not it is caused by water? Also, has anyone removed the cover on a Coleman Mach to access the bolts to tighten? It looks like it involves more than just removing a few screws.
2003 Trailblazer EXT V8