I have a 2007 Yukon xl SLT and we tow a horse trailer. The whistling wind noise from the very back window (on the back door) is unreal. The window has a seal but it does not seem suctioned very well. Does anyone have this problem or know what to do about it? This noise is only when we tow.

I have a 2007 Yukon xl SLT and we tow a horse trailer. The whistling wind noise from the very back window (on the back door) is unreal. The window has a seal but it does not seem suctioned very well. Does anyone have this problem or know what to do about it? This noise is only when we tow.

use duct tape to troubleshoot the noise location...tape a small section at a time to find the problem...

most likely a door alignment/worn pins,,,etc...