2. Consumers want reliability and 100% availability. Consider Uber and Lyft that promise this, except during surge pricing periods. People hate this. It's economically correct in the case of Uber and Lyft, and an obvious idea, but surge pricing during rush hour isn't going to work. People will still own their own cars.
It depends on the alternatives (public transportation, flexibility of demand to go one hour earlier or later, and telecommuting etc.) but surge pricing makes a whole lot of sense. Especially when working on a scale where the surges will be known in advance, can be pre-booked etc.
It will be fine to charge 2x the "base price" for an 8.30am commute if that is what people are expecting to pay. Current hostility to surge pricing seems to be based mostly around the lack of clarity as to the actual price.
3. Personalization and customization. Hey, I like my cars stock, but I still have my stuff in the center console, my presets on the stereo (yes, 760 am in the morning, I'm a dying breed), and my iPhone paired to Sync.
This is already partially solved, Spotify will sync with your uber to play your desired party playlist on the way to the party. In the future, this kind of interoperability will become more ubiqitous.
4. Toy haulers. You're not going to call Uber or Lyft to tow your trailer to a state park or tow your boat to a launch. And this isn't 99%'er speaking, this is blue collar worker in my part of the country.
While some very specialist tasks might not be suited to a "time share" model, as the world moves to such a model it will become MUCH more economically costly to run your own vehicle - so the price point at which a specialist time-share service for minority use-cases will move down significantly.