I would be 99% happy regarding autonomous driving if I got a platooning hardware kit installed into my car so that on highway I could connect behind another car/truck that is going to same direction than me and take a nap or watch a movie. This should be easier problem than full self driving car by orders of magnitude, and I do not quite understand why platooning gets so small share of the self-driving hype.
The first driver ("platoon commander") would still need to be human. I'm not sure people would sign up for this, as your error could result in deaths of people in cars following you.
Anyway, I am more thinking the platoon commanders would be truck drivers that already have legal requirements for rest and no capability for speeding in highway.