I've noticed that most cars have a heater that takes a few minutes to start after the car has been started, presumably because it derives its heat from the engine which hasn't heater up yet.
Are there heaters which don't use engine heat and thus start up at once? What are they called? Can you add it to an existing car or does it have to come with the car? I really would like to get in to a car that blows hot air at me right away.