SmartRide's air spring for the Rear Left of the the 1999-2003 BMW 5 Series Wagon (E39) with rear air leveling is a rugged aftermarket air spring that will affordably replace your leaking air spring. The SmartRide air spring provides a smooth, comfortable, ride and offers an exact fit for quick installation. This spring is made with a durable rubber air bladder and impact resistant plastic top and bottom mounts and includes a new seal kit. SmartRide's economical aftermarket BMW air springs provide O.E. like form, fit and function and are designed for many years of trouble free driving.