World Rallycross Championship 2019

[crossfades]

Supernationals are actual cars unlike RX2 and built upon regular car chassis. 2400 is the maximum allowed size of the engine in that class while Supernational can run anything, although I think they have to add weight to compensate depending on how big engines they run.

And yes, you can mix cars and engines however you like. Otherwise there would just be Volvos and some BMWs.

I don't know the costs of running a supernational but I can't imagine them being too high really. The cars are fairly simple, you can run stuff yourself and they are fun to drive. Tommy Rustad for example went to supernational after quitting STCC and before doing Supercars again.