Car dealers have very little margin in the sale of any car. They get most of their revenues from the services they offer (PMS, mechanical/body repairs, parts, fluids, etc.) Besides, they will only refer you to a dealer if you need to purchase a car. This is to protect their dealers.

Think of printers. You can get a printer for as little as 1.5-2k. It it's the sale of consumables like ink, toner, printhead, imaging drum, etc. is where they get most of their revenues from.