This probably only applies to the GMT900 Escalade, but I fixed the loud wind noise at highway speeds. The Escalade has this weird window seal / plastic exterior trim. It seems that after a decade, the rubber seals on this piece wear out and the retaining clips break.

These pieces are over $400 for both front doors, so I really wanted to believe it could have been something else. I replaced the mirror gaskets (like $10 each)... that did nothing for the noise. I replaced the driver's door seal (like $100)... that did nothing for the noise either. I had hope on this one, since I tried the dollar bill test on several spots and it failed in the top back corner. I also had water coming in from what I thought was this area when going through a car wash. After replacing the door seal, I still had the same noise and the same water ingress.

So, this past month I was able to work enough overtime hours to justify buying new window seal / trim pieces. No more water leak, and the wind noise is gone! I tried to measure the sound difference using a decibel meter on my phone, but my phone (even with external microphone) adjusts the volume before sending the signal to the app. I would estimate that the wind / road noise dropped close to 10 or 15 decibels! I can now talk to my passengers when going over 60 mph.

Anyway, if you have wind noise, it is an easy fix... took me about an hour to an hour and half for both sides. I watched this guy's video to get an idea of what to do (and what not to do):


Here is my old worn out driver's side window seal:





As you can see, the rubber is all crumbling and most of the clips either broke off, or were no longer holding tight.