At the Google office building in Mountain View, California. There are more if you turn around.
Link (thanks Oliver)
Similar Street View images
Two in One: Google cars facing the rain and Google testing its new compact camera
Four google cars and the obelisco
Look there are 6 cars Google Street View
The ‘thinnest building’ of Maringá
New google camera
Old VS. New
Google takes photo of itself
Six wheeled cars are popular in Los Angeles
2 google maps street view cars taking photos of eachother
Whoever did this, I made a copy.