I have noticed something strange with my '05 GXP. If I have the sunroof open more than 3/4 of the way, there is a wind turbulence/buffeting resonance that really gets annoying between 35-38 mph. Even if I roll down both front windows, it makes no difference.

I also noticed that my Bonneville does NOT have a pop-up wind deflector when the sunroof opens like my '01 Alero did. Is it supposed to be there or did someone on the assembly line forget to install it? Does anyone else notice this problem? Thanks!

Try rolling down the back windows some. It helps give the air a smoother exit from the car'* interior.

The wind deflector on mine only pops up about a half inch above the roof. Same thing in mt 02 SSEI. If you use the express open feature it will not go to the full open position. No turbulence in this position. I am guessing that the engineers programmed it that way.

I checked my sun roof yesterday. I have no wind deflector whatsoever. I wonder if it was mistakenly left off my car?