Hi all, I'm new to the forum and would love some help. My daughter's '99 323i starts making a buzzing, roaring type noise at 55 mph. It sounds like it is coming from the right rear. Had the diff, wheel bearings, brakes and wheel checked. All checked good except for the rim, it was slightly warped. Put the spare on....no change. You can put it in nuetral, accel, decel, doesn't change. The noise starts at 55 everytime and goes away below 55. We all know it is boring as HELL driving below 55, so...... Any ideas? Could it be an aerodynamic "buzz" from something underneath?? Thanks in advance for any advice.