BMW540i Rear Air Suspension Spring Set. Brand: Unity. Fits Years: 1999, 2000,...BMW 540i Rear Air Suspension Spring Set. Brand: Unity. Fits Years: 1999, 2000, 2001, 2002, 2003, 99, 00, 01, 02, 03. Air Suspension Spring/Bag Kit -- Kit Includes (2) Rear Air Springs; With Self Leveling and Sport Suspension Air Spring Kit -...more