Let's take a top heavy vehicle like a bus, and then go slide it around a busy highway. Let's make sure there are lots of people inside with no seatbelts. Let's leave the windows open. This is Hagwalah.
Apparently some Saudis thought that riding on this out-of-control bus was a better way to spend an evening than engaging in some less dangerous activities, such as defusing land mines while blindfolded or base jumping without a parachute.
Do we really have to remind people what happens when you try hagwalah without seatbelts?