I like these cars, however I currently have a 2007 GEM car (used I be marketed by Chrysler, think glorified golf cart) that I use to tool around Fleming Island and I have experienced one effect, the only sound is the tires on the road, and this WILL startle bike riders, joggers, dogwalkers. The USPS uses electric vehicles to deliver mail in NYC and they are creepy at times.
I believe the biggest problem is overcoming peoples fear that they will be stranded without power. Even if we never travel more than 40 miles from home, we like the fact that we can if we wanted to. That after all is why we ride cars instead of horses.