These are the hand controls for paraplegic rally driver Albert Llovera, currently taking on the Dakar. As you can see he has a pair of rings attached to the steering wheel, one in front and one behind. One controls gas while the other brake. I've seen a few paraplegic race setups before but I find this one particularly impressive, it makes it possible to work the gas and brake without taking a hand off the wheel, and with the wheel in any position. Conceivably it should also be possible to be on both the gas and brake at once, which is very useful in rally. I like it.

EDIT: Here's some videos of Albert in action: