The motor on the back of it slides the clamshell looking things (the intake runners) to make them shorter or longer to tune the engine (based primarily on RPM, if I recall correctly). I'll try to post some material about it later this evening.
White 2007 Alpina B7
Supercharger clutch/bearings (check DIY), sunroof seal, quarterto8's 6000K angel eyes, bumper side mounts
Black 2002 BMW E66 / 745Li (sold)
KW v3's, blue angel eyes, 8000K headlights & HID fogs, rebuilt alternator, sunroof seal, CCVs, NGK Laser Platinum plugs, sway bar bushings, battery, timing & valve cover gaskets, valve stem seals, guibo joint, mechatronic sealing sleeve, trans fluid, alternator bracket mounting gasket, sanded headlights...