Whoops… Looks like we covered this already. My mistake.
In case the name didn’t tip you off, this fun little kart was inspired by MarioKart. The goal was to build a functional go kart that could be controlled via the Nintendo Wiimote. They did a pretty good job and kept it fairly simple too. They designed a frame that vaguely mimics the shape of the carts in the game. The steering is handled by a 4″ stroke linear actuator. This was initially hooked directly to the tie-rod, but they found it to be too slow. Their solution was to put a lever in between the two with a 1to 3 ratio. This made everything much snappier.
Though they were capable of implementing PWM on the motors in their hardware, they opted to stick with full on, full off because of the push-button nature of the controller. The connection and communication are handled with an Arduino and they don’t mention what bluetooth module they use.
You can see in the video below it is fairly responsive and has more than enough power to lug a passenger over some varied terrain.