navin in KC

I am considering a D5 S8. When do we think they'll be available stateside? I could save about THIRTY THOUSAND DOLLARS if I went with an S7. Apart from the low roof in the back seat and the shape of the car (obviously) and lower powered engine, are there other differences?

Are the features and options and the overall technology the same between the car? While sitting in the car (without looking in the back seat) can you even tell any difference between the two vehicles?