Road Job!
I found the hardest part is to keep your eyes open the entire time. Some people have a tendency to close their eyes at a particular momment.
I had a lady friend, in my sinnin days who wanted to be totally naked when about to have an orgasm. This was very risky in a moving car when the car next to you is a van or truck.
While I developed a habit of driving with one hand on the wheel, I look back on it fondly, but wonder if the risk was worth it.