- The relation of the bottom of the panel extending below the NASCAR vehicle's front bumper or its ground clearance affects the amount of front downforce the vehicle creates. Lowering the valance creates more front downforce. Also referred to as "front air dam."
- An area of revolving compressed air. In wet conditions, race cars can produce vortexes off their rear ends or wings. These vapor trails are similar to those produced by the engines of jet planes.