How long until someone puts a personal gym inside a self driving SUV, so you can workout during your commute? I can imagine people running on a treadmill inside a car while it is stuck in traffic. Or at least sitting on a trainer.
And feed the energy back into the motor. Or even directly power the wheels. It could work if you make the car more lightweight and use a pedal system on gears instead of treadmill. Let's call it a... "Bicycle". :)
That would be pretty great. How do you handle the movements of the car though? Bumps in the road and stuff like that?
Or just a bed.
Given that these cars are supposedly going to strand us on the side of the road (or in our workplace parking lot) on many snowy winter nights, they had better have beds.