They wouldn't have any more work on replace standard vehicles. The principle is the same. Difference is that instead of replace an actual car, they would replace a generic one. But the replacing would still be necessary. And in the other side, people who actually want the cars would need to replace generic cars either!
But let me be straight, which cars you don't like so far, or which car that you want and haven't seen on the list so far?
Edit: If they need to replace 200 cars they don't like, they would need to replace 200 generic cars they also don't like. See how that's quite pointless? The replacing cars would still be necessary, also the massive work. But with generic cars, that is work for everyone, with already added cars, it's work only for those who doesn't like the cars.