The sock works *ok*. They tend to slip around and look silly. My wife has a pink baby bootie on the metal knob in our Saleen. It keeps your hand from burning but looks a little out of place in the car
I am seriously looking to into getting some gearshift knob "cuzzis" made. There is already some demand out there with some of the current cars. A nice tailored slip on cover for those hot months.....$9.99 I think.