text: First and foremost, the sensors on the smart cars. It must take a fortune to buy and apply every single little sensor thats need daily on the rode. Plus it must take alot of people to do that and you have to pay them a lot as well so that means you're going to spend so much money that you're going to try and sell it for a huge price of change that no one has to spend. Or the timing, it probably take one/fourth of the time it take to make that robot car.