While there are plenty of toy vehicles, drones, and other toys that can be remotely controlled via an iPhone, this video shows off the ultimate toy, a Land Rover, being driven via an iPhone.
It appears to be the belief of Land Rover that potentially offering this type of remote controlled functionality via a smartphone would provide owners with the ability to maneuver the car out of difficult situations or to guide it through rough terrain at a maximum speed of 4mph. The company certainly makes a convincing argument but has not confirmed whether or not it actually intends to sell vehicles with this feature built-in.
The system would also be capable of selecting individual gears, steering the vehicle, braking it to a complete stop and accelerating it to a maximum speed specified in the remote control mode.