Model S has many useful features, but some omissions are missing. May be they did not have time. Even if the battery drain was too much, they could have given the option of turning them off when range is an issue:
1. GPS map need to have options to orient to North>South or direction of car.
2. Smart cruise control, including auto stop and auto resume. Useful in stop and go traffic.
3. Rear camera needs guides
4. Need sensors to prevent bumping during parking, etc.
5. Lane assist with warning, braking if needed.
6. Multiple cameras.
7. Bird eye view of traffic with camera data.
8. Heated steering wheel along with heated seats. Save the use of heaters. Rear seats too with on/off switch.
9. Supercharger network, regular charging stations, weather, road/terrain, etc need to be mapped on the GPS. It should give a trip solution, so that the driver know what speed to drive, and where to charge.
In all fairness, the company has done a great job with the car electronics. A lot of this software and hardware will have to take time given their focus on manufacturing efficiency, supply chain, Supercharger deployment, Model X, etc. The good part is that Mercedes and Toyota have the hardware components needed and their costs go to be low.