Tesla is rolling out its Autopilot software to Model S and Model X cars built since October, which are equipped with second-generation Autopilot hardware, according to a tweet from Tesla CEO Elon Musk. The cars have been without a litany of safety features that are available in many older Tesla cars. The Autopilot software is being deployed to eligible Teslas over-the-air, and owners will not need to do anything special for the software to be downloaded.