I think that you are looking for one of these:
http://www.schrothracing.com/store/T...ick-fit/qf-bmw
or one of these
http://www.schrothracing.com/store/T...it-pro/qfp-bmw
Unfortunately, they do not yet make them for the E90 or E92 M3's. I didn't feel a real need for one of these at The Glen on PS2's, but they would have been appreciated at Summit Point. This year I'll be running a 6pt restraint in my E46 track car. I can't wait