The Roadster had a radically large battery. Model S was the first EV optimised car with underfloor battery, compact motor layout, the big driver interface screen and autopilot. Model x delivered the Falcon wing doors, large windscreen, novel second row seats and chemical warfare quality air filter in a package that builds on the Model S. Lower price M3 cannot just be smaller without the expensive bits of MS and MX. It will surely have something radical - and not just in body design. Going from two motors to four would be a radical change. A smaller, cheaper car will surely offer less horsepower. SpaceX uses nine small rockets in its Falcon 9 first stage. Why not a 70 to 100 h.p. motor and transmission for each wheel? Each corner of the car could have drive-by-wire controlled steering, suspension, motor/transmission (planetary gears) and brakes - see image. Autopilot would have an easier job of parking the car in tight places. The vehicle assembly task is much easier. Also, the car could have a single control box for the autopilot, battery, lights, navigation devices, airconditioning, motors, steering, suspension settings, brakes, door handles, windows, etc., that interfaces with the screens in the cabin. All the cables and tubes would simply plug into it for easy installation and replacement. The car would still need a steering wheel connected to the front wheels. Once the body was built, it would simply be a matter of bolting on the four drive units, the battery, the control unit, and plugging all the lines into the control unit. The factory robot count could be halved compared to the MS and MX.