Originally Posted by UltimateBMW
If the rear windows are really powered now, than those motors would probably explain the weight discrepancy between EU and US models. And also why the Coupe and Sedan weights are closer together since the sedan already had rear automatic windows.
The rear window is operated by a small motor and a simple mechanism in my E46 coupe since it's not a conventional window. It just kind of slowly pops out a few inches. I can't see how the motor and mechanism can weigh more than 5lbs per side.