ENTIRELY CUSTOMISABLE racing cars. That means you're given a car, and a stock of carparts including engines, gearboxes, wings, flaps, sidepods, diffusers, rims, airboxes...etc, and you can build-up your own car or chose the parts that will best fit the track you want to race on.
To make things easier if you don't feel comfortable with creating your own car, each car type ships with several upgrade packages that are designed to fit various racing series levels.
ALL PART CHANGES will affect the physics and thus, car behaviour, depending on which spareparts you install.
Allowing to change almost everything on the car is linked to a yet unseen damage model; actually, cars models are built like real-life ones: you have a carbon monocoque or chassis on which parts are fitted, and all these parts will break away during a crash, resulting in the most realistic damage model so far.