I assume people start their cars to warm the cabin. I expect there are much more efficient ways to warm the cabin than using excess heat from an internal combustion engine under the hood. Perhaps the solution is to provide a way to warm the cabin (including seats and steering wheel) very rapidly when the car starts, or provide a way to warm the cabin without starting the engine.

The latter solution requires an energy source. Perhaps a hybrid car's batteries are it - not an option until recently, but hybrids are now relatively common - and the energy could be used efficiently: Ambient air heaters, of course; plus heaters directly in seats and steering wheel to warm them more efficiently than the ambient air would; plus of course sensors to shut down heaters when things are sufficiently warm.

OT: Did the NY Times change their layout recently? For the first time, IMHO, it's gone from functional to appealing.