But they can only be produced at a finite rate, which may cause competition amongst buyers in the short term as they bid against each other for the finite number that are on the lot.

Further, the resources needed as raw material are finite (unless we start asteroid mining), as is the energy needed in the process: we have only so many gigawatts we can produce at one time.

More plants can be built, but those take resources as well: some of the very same resources that are needed to build the cars we're talking about.