The tracking of the rear wheels is as important as the tracking of the front. Any misalignment at the rear will give the car a loose or "slippery" feel under cornering. All the handling and tire wear conditions discussed under front end alignment apply equally to the rear; at the rear they are often harder to diagnose and cure.
On all but the Multi-link rear suspensions, the position of the rear wheels is fixed in all three dimensions by the correct location of the components. Any tire or handling problems not traced to other causes will require replacement of suspension parts. The alignment dimensions-caster, camber and toe-can be measured on an alignment rack but are not adjustable.
It should be noted that any time the rear wheel alignment is checked, the front must also be checked and set. Ideally this is done on a four wheel alignment machine which will provide data on the comparative front and rear track as well as each front and each rear wheel.
Simultaneous four wheel alignment capability is REQUIRED for cars with Multi-link rear suspension. Failure to use the proper equipment may result in the rear wheels having a mind of their own and steering in other directions than the driver might like. This "rear steer" effect can feel like roller skating on an ice rink; find an alignment shop with the proper equipment and get it done right. Volvo dealers are required by the manufacturer to have the proper equipment.
The Multi-link suspension is adjusted for camber and toe through the use of eccentric bolts in the suspension links. The camber adjuster is located on the inboard end of the lower link. The toe adjuster is located at the inboard end of the track rod. Neither should be adjusted by anyone who is not using a four wheel alignment machine and the specifications book.
An additional adjustment controls toe variation. Although the toe setting can be numerically correct with the car at rest, it can change as a function of load and suspension motion. This very minor change can greatly upset the handling of the car. By inserting precisely sized shims between the upper control arm and the wheel bearing housing, this minor variation can be further controlled. This is particularly handy if the car constantly has a load in the trunk or constantly carries several people. The rear suspension can be fine-tuned for the best road manners under given load conditions.