Jill in the Box
The action taken such that when having sex in a car with a sun roof, the man thrusts upward so that the woman's (Jill) head emerges through the sunroof and moans in delight. Similar to the childrens toy the Jack in a Box especially when performed with random thrusts.
I was dogging in the park last night and whacked it while watching a Jill in the Box.