I'm thinking about getting a couple of these attached to my steering wheel, at the five o'clock and seven o'clock positions. My arms get pretty tired after a drive and I think this will allow me a more comfortable way to hold the steering wheel. I also think it will give me a little bit more leverage for steering. Before I can have these installed, however, I must meet with a driving evaluator who will recommend the best product.
Clearly this is not something I can make myself, using Allen wrenches and foam tubing.