Not to make a big deal out of this. But, I'm trying to picture how someone can get blisters just from driving. I can see someone getting blisters if the vehicle they're driving is some kind of huge truck with no power steering and the wheel alignment is so horrible it swerves as soon as you let go of the wheel. You're constantly battling to keep the truck straight on the road.
But a car...... Gee, my 06 Hyundai Sonata is a big and heavy car. But I can drive it with one right thumb and index finger on the steering wheel while my left arm is draped over the open window and me trying to look cool.
My chances of getting blisters are far greater handling exercise machines in the gym.