Tesla has publicly stated the Model S would be similar in size to the MBZ E class or the BMW 5 series. At the time the comments were made, the Audi A7 had not arrived on the scene and no comparison was possible. Like the Model S, the A7 is a 4 door hatchback design. However, seats 4 rather than 7. I am posting the exterior dimensions of the A7 as they are very similar to Tesla's published dimensions. For those that are unable to see Tesla's prototype, I think viewing the Audi A7 in person should give you a good idea of the size and proportions of the Model S.