The main changes on the car to go from road car to race car are on the outside.
The race car gets big, wide and lightweight Volk Racing wheels.
The front fascia and fenders are wider and subtly shaped to lower drag.
The front fenders are significantly wider to help cover the wheels, but also to help evacuate air from the wheel wells.
The gigantic goose-neck wing is a spec part for the TCR series.
The wing is arguably the least "this could be a road car" part of the car.
The TCR is powered by a turbocharged four-cylinder engine that makes around 350 horsepower.
The single center-exit exhaust is unique to the race car.
Click or scroll through for lots more pics of the Mazda3 TCR race car.