a Mexican Dumptruck is using a pickup truck to dump a load of cargo similar to a dumptruck. The load is placed in the bed of the truck and the tailgate is left down. The truck is driven in reverse at a high rate of speed towards the intended "dump" point. Just before reaching the "dump" point the driver slams on the breaks causing the cargo to come flying out of the truck.
"I don't really want to unload all this firewood by hand... let's just do the ol' Mexican Dumptruck"