[hsqrd]

Bought a 2007 Burb to replace my 04 Yukon XL -everythings great except when I tow my horse trailer - approx 5200 loaded -dual axle. There seems to be a vacuum created at highway speeds-55-60- bwt truck and trailer which pops the rear window seal and makes a hell of a racket. anyone else heard of this or suggest a fix-still under warranty

 

[JRM3]

Take it back for warranty, or get some good adhesive and glue it.

 

[ChevyFan]

That will be a long-term issue, even if you do it yourself. Get it fixed and documented under warranty.