They don't need to when they are doing this :

"One solution is to reel in buyers with an Amazon-like service model. It will bring the cars to you for a test drive, let you order the car online and deliver it directly to you in a transparent truck. When you need service, Genesis brings you a loaner and takes away your car. And the set purchase price – there's no haggling – includes service for five years."

I doubt very much BMW will do that for a 3 series.