Without seeing the other comments here, my first thought was "Why target electric propulsion only?"
So, I ended up putting through a similar comment:
So, I ended up putting through a similar comment:
Modern cars have become very quiet at idle. Examine a high end luxury car, non hybrid, non EV and you will find that it is practically silent at low speeds. If low speed noisemakers are a good idea for quiet cars why not set a minimum noise level for all cars, not just hybrids and EVs?