Steering Axis Inclination
WARNING: This page is about a different car, the 2006 Suzuki Verona. However, it is still accessible from the selected car via links, so may be relevant.
Steering axis inclination (SAI) is the tilt at the top of the steering knuckle from the vertical. Measure the SAI angle from the true vertical to a line through the center of the strut and the lower ball joint as viewed from the front of the vehicle.
SAI helps the vehicle track straight down the road and assists the wheel back into the straight ahead position.
SAI on front wheel drive vehicles should be negative.