Self-driving cars have been in the news a lot recently, but in most cases you'd need to buy a new car with the autonomy built in from the beginning. Cruise, a 7-month old startup, is taking a different approach. They've just sold 50 pre-orders on a self-driving car kit for $10 000 each. The sensors are mounted on the car's roof with a company in the car's boot. It might not resemble the concept cars you've seen at CES, but it may be the way forward for driverless technology.