Instructions are inside the scene. It runs at 100 hz. This one took me a couple of hours to build. It got confusing really quick, but I think it ended up great. The driver controls the car from their seat using only the power of the limbs. It uses minimal thyme and mostly mechanics to set it in motion. It is at the scale of a regular hobbit, so scale is somewhat realistic (the values used for each object were mostly from Algodoo's preset materials[density assumes that each object is only 1 mm thick], with a few exceptions).
Sorry, the mechanical brake is purely for show. For now, braking is done directly via the hinge control of the front wheel. Just change the collideset and friction of the stopper if you want to try the mechanical brake out (hint: it doesn't work well).
This was a lot of fun to make and I hope you experiment with the car. Please rate and comment as I appreciate the feedback very much. Thanks!
Feel free to ask if you were a bit confused. It's nearly 2 AM here and I'm a bit loopy.
EDIT: Everything is naked because I like to see the mechanics of it all.
EDIT2: Updated the engine a bit and fixed the brake. The brake should work now. Prepare for a tone of vibrations when the clutch is disengaged.