I bought the front and rear package, but it comes with 2 front sensors, which is useless. The rear sensor is a much longer cable, so either keep you rear, or shell out the $20-30 for a new one. I cut mine off, but iDrive won't let me reset the service required for the rear until I have a sensor again. Front replacement was fine and reset without issue.
2009 Sapphire Black Metallic E90LCI 335i xDrive: 19" Morr VS8.2 Wheels, KW v1 Suspension, Lux Angel Eyes, Performance front splitters, Tinted, Cobb Custom Stage 2+ Tune, Cobb FMIC, AR Catless DPs, R1 Concepts' Rotors w/ Hawk HPS Pads