E70 X5 Road/Wind Noise from Rear Area
 

All,
While diagnosing the dreaded trunk rattle which now appears to be fixed by padding the u-hooks on the lower tailgate, I noticed from riding in the backseat that there appears to be reasonable road and wind noise coming from the rear of the car. It's audible from the backseat (2nd row), but not really audible from the front seats (so it's not that bad).

It becomes audible around 50ish mph, and it seems to be coming more from the rear driver's side corner, but I haven't thoroughly diagnosed that.

The tires are new, Bridgestone RFTs with around 4k miles on them, but it doesn't sound like tire noise, more like slight wind. It's also possibly a wheel bearing, but I don't know enough about the sounds and haven't spend enough time to diagnose it.

It's pretty faint, and I doubt most people would know, I'm just anal about things like this. Any known areas I should check? I noticed the rear quarter window seal on the drivers side seems to have a slight area about 1cm wide where the seal isn't exactly perfect, but it's so minor that I don't know that it could be the source.

Here's a picture, and to clarify this is the backmost glass on the side of the car (the window in the trunk).

https://dl.dropbox.com/u/112537/seal.jpg

Any other things I should look into.