The only city shown at night in Street View is, of course, the city that never sleeps: Las Vegas. It might be that it never sleeps or maybe is the only city with so many lights that at night, that it looks like day light, and the Google car can take pictures. Also there is the theory that the Google drive went to play to the casino at the Mirage and forgot to stop the camera...
Cuortesy of: Jaime
360º picture in Google Street View
Position in Google Maps