The dealer usually has some stock of the most common models and configurations that you can purchase right away. The car is custom built only if you don't like

The dealer usually has some stock of the most common models and configurations that you can purchase right away. The car is custom built only if you don't like any of the available configurations (mostly happens for non-popular colors or extras). Also dealers can co-operate and if one doesn't have the configuration you like, he may search for availability from other dealers.