'Scams' used for vehicle hijack / robbery.

[ClassicCruiser]

In view of the increasing number of reports of vehicles being stopped for hijacking / robbery (or worse) - I wondered if it might be worth reporting some of the methods used to actually get the vehicle to stop in the first place.
Of course the methods employed will vary enormously between say Spain & Northern Mali, and it is likely that there is little one can do to avoid the situation - but it prevents one incident it will be worth it.
Anybody got first hand experience or reliable accounts?
Steve