How about an on/off ignition system so we can bump-start cars by pushing them and dumping the clutch in gear
Hey. it can already be done. if you have manual clutch and gears and then shift to 1ste and make the car stall, using the node grabber or gravity down a hill with clutch in and then dropping the clutch will kick start the engine back to running.
That has been implemented looong ago. The only time it doesn't work is when you manually turn off the engine using the respective button instead of actually stalling it