Numpad 4, 6 - rotate crane
Numpad 8, 5 - change crane pitch
Numpad 0 - toggle magnet on/off
Numpad subtract, add - change magnet height above ground
You can leave an vehicle in an place to trigger the automatic mode:
or go to the control place and control the crane and magnet:
you can pick more than one vehicle:
Actually should work only in the GTA 3 Rage Classic mod, I'm planning to extend this to GTA IV/EFLC, but i need to find some models first.