Anyone can put a computer in a car and, using remote controls, nearly anyone can control a car's electronics from a safe distance. Controlling a car remotely using an iPhone and installing a computer that can run without the addition of a new battery is something entirely different.
This trick, though nerdy, piece of kit, uses a small Alexi computer running Linux (Ubuntu) and hooked up to a 3G connection. Using the browser on his phone and a lot of brainpower, he can now access the OBDII data and control his audio system, motor, locks and other electronics. Even better, instead of using a direct wifi-to-wifi connection, he connects to the Internet and then the car downloads/uploads the information. This means he can connect to the car from in his house or, if he likes, in another part of the world.