Brey Krause R-9229 Passenger Sub Belt Mount - R-922x Seat MountThe Brey Krause Model R 9229 Passenger Side Anti Sub Strap Mount is designed to mount directly to Brey Krause's line of R 922x Side Mount Adapters that fit any BMW E46 3 Series model (including the M3) or BMW Z4 (E85 E86). The stainless steel bar attaches directly to the factory OE slider and helps properly locate the Anti Sub belt for optimal safety. Moves together with the slider to keep the belt properly located and at the same length, regardless