Maybe the companies have too many car models for that to be feasible anymore?
It looks like Tesla will specialize in a handful of types with iterative improvement which will work in perfect tandem with this approach. Kinda like Apple's hardware.
As an aside, it's really, really weird to see comments allowed for what is basically a press release.
You can clearly see the dealership in the mall in the Blues Brothers for example ("The new Oldsmobiles are in early this year!")