Re: If you want a prime example of how not to drive...
The consensus on t'Reddit seems to be that it was just dirt being washed off the top of the truck, which is literally the most boring explanation possible.
What amused me was the way the driver reversed, the truck hit the overhead roof beam, and his passenger got out and looked everywhere except up.. "nope, there's no curb behind you, we must have imagined that loud crash and the truck almost coming off its frame, try again... repeatedly..."
Biting the hand that feeds IT
