>If you were to actually try engaging reverse while rolling down the road, the gear that has to slide into place is going to be trying to engage two spinning gears, and one of those gears is rotating rapidly in the wrong direction. What you will hear (and feel in the shift) is a very obnoxious buzzing sound as the teeth gnash against one another. However, there's no way to get the gear into place while in motion like this, so nothing will happen. The transmission won't explode. Nor will the car stop on a dime and reverse into oncoming traffic, even though that's what happens in cartoons.