They had to drive one of those cars through London at night and have no-one complain to find that they were quiet enough. The races take place on city circuits with road tyres, all very quietly. There is music played during TV action replays. Saw The Moscow E Prix last weekend. Missed the other ones this year. This is the first year there's been a Moscow one.
Next Saturday is the London E Prix and - presumeably as part of some promotion - Boris Johnson is going to drive a Formula E car - not in a race, of course. The races are all very serious, with experts that have moved over from Formula 1. There's a Chinese team, teams from all over the world, India are in Formula 1; also in Formula E. Virgin are in it, they have their own team.
The previous races of this year, are all available to watch on the official site: http://www.fiaformulae.com/ and they say you can watch live races on there, too. When you go to the page to watch, (probably after you select your country) it has a countdown to the next race. Below that are the previous race videos to select
Those things are so freaking quick, and so quiet. You can hear them riding the curbs.