You still need the key to drive the car. All remote start systems will kill the engine if you hit the gas or change gears without the key in the ignition. What I want to know, does this system have a larger range than the key fobs? Usually I can see my car from my office, but the car can't hear the fob. It's nice to start the car, then get my coat on and go out to the car. By then the seats aren't exactly like sitting on a concrete bench, at -40F that foam rubber gets freaking hard.