The auto industry is ripe for a total upheval. If you don't believe it, read this article that was originally on Quora and then picked up by Forbes about industries in general, then check it off against the auto industry: Four signs an industry is ripe for upheaval.
Tesla's just the vanguard, the tip of the iceberg. For what wll really revolutionize the industry, see Laminack's Law of Technology.
Once Telsa becomes successful, it will leave behind a wake of n-1 generation technologies that will suddenly become a LOT cheaper. Here's some other factors that will be contributing:
The nascent open hardware movement. There are several open source automotive platforms, but they haven't gained traction yet because they haven't reached scale.
Next: Auto manufacturers (OEMs) hate their distributors and vice-versa. There is no economic reason for car dealers to exist anymore. These need to be replaced by distributors, not dealers.
The manufacturing of drivetrains and bodies needs to be distributed, done by smaller manufacturers in many places. This eliminated huge start-up costs and eliminates single-point-of-failure supply chains.
Cars can be assembled on-site and built-to-order. Car bodies will be stocked in one color: primer. They'll be painted to order on-site. Why not? There are a number of national paint-and-body chains that can do this. But can a car really be built while-you-wait? Yes. If properly designed, a car can be easily assembled and disassembled. The advantage of this is greater flexibility for the customer and substanstanial cost savings for the distributor, since they don't have to floorplan 100s of different styles and colors.
The drivetrain will be the n-1 generation of electric drives. The console can be a generic android touch-screen tablet that 3rd parties can write software for.