[Traveller]

Here's the layman’s answer.........

As you accelerate, the driveline torques over and weight transfers to the rear causing it to "squat". If you abruptly lift off the throttle during that hard acceleration the opposite happens:

1) the motor torques back

2) the rear "un-squats"

This can cause the rear end to become unsettled and, in a short wheel based car, traveling at high speeds, the results can be very…….well……."exciting".