Gauges move after car is off

This happens on a lot of GM vehicles but no one notices because they're already out of the car. I suspect it is due to the counterweights on the pointers. The gauges haven't had spring-loaded pointers for many years. Instead, they simply sit on a magnet that is pulsed to various positions with varying voltages and polarities on four coils of wire. There's nothing to hold the pointers anywhere when power is turned off. All you need to be concerned with is the pointers go back to their proper positions when you turn the ignition switch back on. Tapping on the face of the gauge cluster will often make the pointers move too.