Many of us have waited behind people walking in the middle of the parking lot aisle, unaware they are blocking a silent car behind them. One hates to honk and startle them; they may stop and turn around. Same thing goes for a strange noise, however entertaining. So you really want a familiar noise associated with a moving car, so they will simply move sideways without even looking at you. Thus my criteria: A moving car sound (say, tire noise; an engine sound could come from a parked car); nothing urgent or entertaining Ability to trigger without removing hands from steering wheel (no new knobs or buttons) Turns itself off in two seconds Compatible with Tesla firmware of the future. An Untested Example Record studded snow tire sound at low speed. Alternatively, driving over gravel. Muffle after two seconds. Mount (Frunk? Nose cone?) a musical doorbell that has a USB port for audio files. Tap the high beam wire for the button push. (Might need a series capacitor for when the high beams remain on.) So when you flash your headlights (a routine warning signal), you will also get the tire noise for two seconds. But this also means that switching to high beams at speed will give you the tire noise for two seconds. (At least it will be the sound the tires make at very low speed!) Improve it. Replace it. We need a recipe.