Just put in 1 or 2 empty bottles w/ lid(s) in the retractable drink holder of the rear center armrest.
http://realoem.com/bmw/partgrp.do?mo...29&hg=52&fg=20 With lid back on, it'll eliminate cig butts from stinking up the car when it's parked overnight.
I use an empty salad dressing bottle (oval cross-sectional shape, almost flattened) for cig butts to keep the smell to the minimum (the bottle is wedged in between the driver's seat and the center console, right in front of where the seat belt clips in).