I went 4WDing in sand dunes in the United Arab Emirates with a bunch of American expats.
On one of the dunes I was on the outside of the car standing on the foot treads holding on through an open window. Part way up the dune the car started to tip, so I jumped away and luckily missed getting squashed when the car rolled.
It was a really stupid thing to do, and I got really lucky. Good lesson for me to have now I have kids - I have a more healthy respect for risk.