EDN has an interesting article:
Automobile electronics seek to plug power leaks, by a Product Manager at Linear Technology. It has some tidbits on LED headlights: "The main roadblock preventing solid-state lighting in cars is the cost. HB-LED-production numbers will have to grow to cause the price drop necessary to include them in Chevrolet models as well as Cadillacs. In addition, temperature changes strongly affect LED-light output, with output varying by as much as 50% over the automotive-temperature range of subfreezing temperatures in the winter to triple digits in the summer" and Switching Regulator sleep states.
There is also some information on both the Volt and Tesla, e.g. "EV manufacturers, such as Tesla, are working on alternative methods for cabin heating, such as relying on seat heaters for localized heat, as well as PTC (positive-temperature-coefficient) heaters for general cabin heating."