There are three options here depending on the severity of your disability.
1) Use a steering ball with your right arm and work the signal and wipers with your left arm with the aid of two levers.
2) Use an infrared steering ball with your right arm. This has several functions on it, which allows you to work the signal,
wipers and other things on the car.
3) Use a steering ball with your right arm and work the signal wipers and other equipment with another part of your body
using a bleeper switch. The bleeper switch can be operated any part of any limb or your head.