Here's what we do:

For vehicles with non-adjustable rear suspensions

1. Angle readings are measured at all four wheels.

2. The steering is centred.

3. Front wheels are referenced to rear thrust line and set to specifications.

Result: All four wheels are parallel and the steering wheel is centred.

For vehicles with adjustable rear suspensions

1. Angle readings are measured at all four wheels.

2. Rear wheels are set to specification. (Rear thrust line corresponds to vehicle centreline.)

3. Steering wheel is centred.

4. Front wheels are referenced to the rear thrust line and set to specification.

Results: All four wheels are positioned straight ahead & parrallel and the steering wheel is centred.