Cars are already ubiquitous and really, really loud. We tend to forget this because we're all so used to it. From the first values I could find with decent sourcing, at a distance of 25 feet, a car driving by at reasonably high speed is 77 dB, while a drone is 65 dB. I live 500 feet from a freeway, with lots of buildings between here and there, and I can still hear clearly hear the traffic indoors with windows closed.