So in a rules context, usually suppressing tanks has no discernible effect apart from “cannot use externally mounted weapons” so maybe something similar for AFVs that already have morale issues, except the crew has deemed to have chambered underneath or something.
If the crew have decamped then the effect is ‘cannot move, cannot fire any weapons’ surely.
This is getting perilously close to the FoW ‘Bail Out’ silliness 
Obvious contrarian and passive aggressive old prat, who is taken far too seriously by some and not seriously enough by others.