(Bloomberg) -- Tesla Inc. is facing increased scrutiny from federal regulators over its driver-assistance system known as Autopilot, with investigators demanding to know if the electric carmaker has made it easier for drivers to take their hands off the wheel.Most Read from BloombergPutin Agrees to Visit China in First Trip Since Arrest WarrantCitadel Vets 69,000 Intern Applicants to Find Next Math GeniusesWhat to Do With a 45-Story Skyscraper and No TenantsCrypto Scores Landmark US Legal Win Wi