Algodoo

I redesigned my spring engine truck used in my gold transporter to have leaf springs (the more realistic the better) and needed some payload so I strapped my wankel buggy to the back. S to start the engine (I disabled the wankel engine), 1, 2, and 3 for the gears, X for brake, Q for reverse, F for four wheel drive.
It's a pretty recent design and I haven't worked out all of the kinks so there's still a little rolling resistance from somewhere in the transmission.