<ul data-eligibleForWebStory="true">A driverless Tesla Model Y was sent to a customer for first-ever 'autonomous delivery'.The vehicle drove 15 miles from the factory to the owner's apartment complex.The self-driving software used for the delivery was downgraded for commercial use.Tesla's achievement raises questions on technology reliability and scalability in autonomous driving.The event showcased Tesla's progress and challenges in the self-driving car market.