I disagree on the statement about not hearing electric vehicles. Most of the time when I hear a vehicle, any vehicle, I hear the vehicle's tire noise and wind/air noise more than anything else. Rarely do I hear the engine until they gun it as they try to get around me. But I can still hear it approaching beforehand. Electric vehicles would be no different as they still have tires and still have to cut through the air.
Then again when going 15 MPH and above there is quite a bit of wind/air noise around my head and ears, and sometimes I think I hear a car when really there is nothing there.
No I don't have any mirrors yet but will probably get a TAL soon. Also considering that one UK-made mirror that attaches inside the front frame triangle just behind the head tube.