When racing, your vehicle will go through a numerous amount of alignment changes. Your static alignment will not be the same as it is the moment you start driving after getting the alignment at a shop. The dynamic alignment is constantly changing with every and any abnormalities in the road. One of those changes from static to dynamic alignment will affect the toe in and out of the vehicle.
Toe plays a pivotal role in alignments both on and off the track. A car with zero toe will have the wheels parallel to each other on the same plane. Throw some toe in and the lines will start to touch each other in the front of the car, and vice-versa for toe out, lines will be crossing towards the back of the car. On a road course front toe primarily affects eagerness of the car to turn and mid-corner understeer/oversteer balance. A car with front toe out will initiate direction changes more easily than a car with front toe in. A car with significant front toe out will feel "darty": a small movement of the steering wheel will be enough to get the car to rotate. Most cars will allow toe adjustment, it doesn’t take a lot of toe to get an immediate change with the cars handling. Whiteline has toe enhancement bushings to allow some extra toe changes if needed.
Picture below is the Rear Steering Bump Steer Correction Kit for Mitsubishi Lancer Evolution IV-IX. Whiteline bump steer correction kits are designed to correct suspension geometry improving dynamic toe settings during wheel travel. A reduction to bump steer results in sharper handling and reduced understeer.