Joe, 45-50 years ago, those spinner knobs were fairly popular on cars and trucks without power steering, and they were also known as "suicide knobs" and frequently did just the damage you mentioned to thumbs and fingers. I've also seen some of the old ones come apart as a driver was turning, and he was suddenly left with a knob in his hand and the steering wheel whipping back the opposite direction. /forums/images/graemlins/laugh.gif There's no telling how many broken thumbs and wrecked vehicles resulted from the use of those things. Probably won't happen with power steering and the modern knobs.