Once you've used the necessary amounts of up-to-date electronic design techniques and components to build the battery management, motor controller and charging

Once you've used the necessary amounts of up-to-date electronic design techniques and components to build the battery management, motor controller and charging systems in your "barebones" EV, adding some multicolour lighting and a touchscreen is a tiny step. A milkfloat is nearest thing to a "barebones" EV.