POWERFLEX PFR5-420, PFR5-420P and PFR5-420BLK are rear subframe front mount bushes for BMWs listed in the source - no guesswork, no compatibility myths.
PFR5-420 (70A yellow): fast-road friendly. Retains comfort while tightening up rear-end response on standard or stage 1 cars.
PFR5-420P (80A purple): stiffer for stage 2 or spirited daily drivers - sharper without jarring.
PFR5-420BLK (95A black): track-day rigidity. Minimal deflection, maximum feedback - best paired with coilovers and a stiffened rear end.
OEM part numbers 33316758259 and 33316792509 are superseded. All three compounds fit the same mounting points - choose by intent, not aesthetics.
