The Model S interior has many surfaces that appear to be leather wrapped, but which of these surfaces (if any) are real leather vs. synthetic? With the seats they make it clear what you are getting - synthetic with the textile seats, or real Nappa leather. However, no mention is made of the seat selection influencing the rest of the interior other than limiting your choice of trim to piano black vs. wood. The steering wheel, dash, and door panels all appear to be the same regardless of seats. I've noticed the steering wheel texture is different than other cars with leather-wrapped steering wheels that I've driven. Is this because it and the rest of the interior is really a synthetic material?