It starts becoming a regular feature in the streets of San Francisco: driverless cars. Google is known to test their autonomous electric cars in the city. But the Google cars are regular cars, like Toyota Priuses, with a kind of radar on their roof. But here’s something very different: a futuristic self-driving Mercedes. The car, which was first unveiled at the Consumer Electronics Show in Las Vegas last September, was cruising around on San Francisco streets for a photo shoot when bystanders began snapping their own pictures. The future is on its way.