The rear wheel alignment use many of the same parameters as the front end of the vehicle. The independent rear suspension exhibits changing camber, caster and toe as the wheels move up and down.
Camber, or the angle the wheel makes with true vertical, can be adjusted with special tools and techniques. The same is true for toe adjustments. It is best left to a properly equipped alignment specialist to perform any adjustments.
To properly align a fully independent suspension as all BMW's are equipped with, both the front and rear settings must be checked and adjusted to compensate for any differences at the front and rear axles. This is called a 4-wheel alignment and allows the front and rear suspensions to work in unison and not work against each other. If the front axle wants to travel in one direction and the rear works on another geometric axis, the vehicle will tend to crab or feel unstable. The front and rear suspensions have to be set to work on a common axis.