I have a 2009 328i sedan w/sports package that has squeaky door seals when going over bumps or when the body flexes.
This is more apparent on the rear doors and the driver's door. At highway speeds (even on bumpy highways), it's completely silent, as if air pressure is keeping the door seals from shifting/rubbing. Before I take it to the dealer, I was just curious if anyone else has come across this?
It appears to be the door seals rubbing against the black shadowline trim. I'm not sure if this would happen on cars with chrome trim. I can completely eliminate it by placing blue painter's tape on the door seals where it contacts the trim. Another way to temporarily quieten it is by applying something like Meguiar's NXT Protectant to the rubber seals, but it returns after a few days. Note that this is just on the upper-most rubber seal, which touches the trim, not the main seal which goes all the way around the door and contacts the metal body frame.
I've searched the SIBs, but the closest fixes are for X3's and 5 Series (links below). You would have thought BMW would have completely gotten rid of those poor seals.
Thanks in advance.