Whoopsy:

To some people, a supercar has to be unique, that includes the engine.

...

It's costly to make a specific engine for a limited production car, but that's THE POINT of having a supercar, uniqueness.

If the engine has to be shared with some other cars, especially a different brand of cars, then that supercar has lost quite a bit of the identity.

I don't think the fact that AMG makes the Zonda engine detracts from the character and identity of the car at all. They make the engine, but its specifically made for the Zonda. Its not like you're going to be at a red light in your 1.5MM Zonda F and a C73 is going to pull up next to you.