We've met sam schmidt before. he's a racing driver who was paralysed in an accident in 2000, and five years ago, he took us for a ride through las vegas in a car that allowed him to drive using just his head and his mouth. so, the steering system, it's an ir camera system and whichever way you turn your head steers the car — he'll turn his head angle into a steering angle. the gas and brake, it's a sip and puff system, so we have a tube connected to a pressure sensor. positive pressure, blowing — that's your accelerator pedal. negative pressure, sipping — that's your brake pedal. the sam...