Most popular Tesla electric car after-market add-on
Big speakers on the outside that broadcast a deep-throated sports-car growl timed by electronics to acceleration and cruise!
Actually, since electric cars are silent, one wonders if eventually laws will require some noisemaker on board, similar to the function of backup beepers.
Maybe something that plays nice music? Nah..a traffic jam would sound like an orchestra tuning up. Unless the electronics communicated with nearby cars, and coordinated the rhythms and harmonies...
Lend a whole new meaning to the word "jamming."
Other ideas: Bird calls?
Any other suggestions?