Software. The differentiating factor is software. Batteries will soon commoditize. What will make cars unique is how effortless they are to interface with, and things like suspension tweaks in over the air updates. Much like the transition from N64 cartridges to DLC, they dont need to sell a finished product any longer, youre buying into an update stream. Buy from a vendor you trust to keep iterating in a way you like (increased features or increased stability.)