Design is about more than the shell of the car. It is about everything, from the touch screen to the heads-up navigation, to the automatic handles, the interior space, and even the fact that it's electric. It's really just an amazing all-around car, and you can't make something like that without designing every detail.
The shell of the car however is the part that us mere mortals can see right now.
Having recently driven a Kia Optima, Ford Focus, Fiat 500 and a couple older vehicles (2011 Crown Vic, 1997 Town Car, 1967 Cadillac) I dont see a substantive difference, the difference in my mind is less a function of design, and more a function of the materiel chosen to implement the design.
All of these cars clearly had a whole bunch of thought put into where the controls are and how they functioned, but what made something feel quality, was the choice of materiel and how well it was put together, the design qualities were more or less equal.
What makes the Tesla innovative to me is the technology in the drivetrain, not the inside of the car.
My personal tastes would dictate having more things labeled with words over say otherwise inscrutable symbols - I rented a 2010 DTS once, it took me 15 min to figure out how to turn either the wipers or the headlights on, because I couldn't figure out what the icon meant.
