I remember hearing a similar story that was supposed to be part of the Darwin Awards. It was around the same as you say where a guy literally mounted a working jet turbine engine to a vehicle. The car worked perfectly but he did not calculate for the time it would take to actually come to a stop so he didn't figure how far he'd go. Which in turn meant he didn't scout his path all the way.
So he takes off and is gone within seconds and it wasn't long the crew drives following the smoke cloud to his location. When they finally got to the site they found a mountainous area far beyond their bounds. The car has hit into the base of a mountain and there was literally nothing but mashed metal indented into the stone. His body they said could not even be seen. With that much force his body, bones and all, would have literally disintegrated and fused with the metal and rock due to the high heat.
I'm sure he didn't feel a thing.
I told the Overseer of Vault 13 I'd give everything to save everyone, and so I did, I saved them all. Since then I've felt loneliness.