Installed an OEM M3/M4 steering wheel with tricolor stitching, OEM competition paddle shifters and OEM hollow lower steering wheel trim. I bought the parts at BMWpartsnow.com. Part numbers are listed below.
$ 35 OEM M3/4 hollow lower trim 61-31-9-882-776
$ 570 OEM M3/M4 competition carbon fiber paddle shifters 61-31-9-501-592
$ 813 OEM M3/M4 steering wheel 32-30-9-882-678
