Or is it some random information from one TV show? What makes you think it is not just some silly joke?
I think what you described: "女人開車的方式是緊張的,緊握方向盤,好像不握緊車就會突然跑掉一樣。" is not true. I for one, only use my left hand to hold steering wheel if I am driving below 50 miles per hour, . I have been doing that for 20 years, half of the time in a car with menual transmission and never had any problem.