Cars that preserve the Earth, kill humans?
Electric cars run on battery-powered motors on each wheels and because the motors are non-audible, these cars could pose a threat to pedestrians especially those who are visually challenged (blind). Running on high speeds causes wind noise and tyre sounds but when doing very low speeds around the neighbourhood, where people are most likely be walking, could be dangerous due to its silent operation.
Excuse me, I ‘announced’ my arrival so I should be the one crossing first!
(Pic credit – Lotus Cars USA, Inc.)
Car manufacturers are advised by the public domain that these cars be equipped with a sound emitting device that can alert the pedestrian as an indication that a car is approaching near. If it is a go for such sounds, I believe the young mod-heads would be at delight as they can put in a Ferrari sound onto a Smart ForTwo car.. 
Pretty neat eh?
More story about this HERE
i think all cars should have the V12 engine sound emitting system in place