Algodoo

I'll likely upload it as a separate save once I reach a final prototype with no problems.
Until then, this is what I've made. The infinite momentum in the "cells" of the wheels
helps to maintain high grip whilst having individual moving parts interacting with the terrain.
Sponges don't work well for this because of uncontrollable cell size and all attachment methods
to a solid core to ensure constant rotation on steep hills having quite large downsides.