A nice feature would the option of the seats giving you a massage, using pneumatic cushions, with different levels of intensity and different massage types.
This would be great for long drives and is currently offered by a few luxury cars.
The seats generally on the 2013 Model S are OK, not great, not bad. They’re quite thin but comfortable, and (on YouTube videos) I’ve seen many seats getting wrinkles in the leather after only a few weeks of use.
Audi, Lexus, and Mercedes offer this as an option on select models. A 2014 Audi A8 offers a rear seat massage option for $3500.
(voting combined from a close duplicate that has been removed)