Not even on forum's free games list...
Sandbox driving, flying, but mainly crashing simulator.
http://www.rigsofrods.com/blogs/
In case you can't find the PC version link in the blog, dig into SourceForge http://sourceforge.net/projects/rigsofrods/

Very vehicle's body is a mesh which goes very squishy under extreme pressure.

Many, many awesome slow-mo crashes
https://www.youtube.com/watch?v=yQZLvl0f7DE

Very loud people, crashing
Cars! https://www.youtube.com/watch?v=VwKHGPQ7k40
Planes! https://www.youtube.com/watch?v=rFKaT21IP2o
Truck! https://www.youtube.com/watch?v=SoTOIr04cKM
Trains! https://www.youtube.com/watch?v=JEXG5usYcPU