A Tesla Opening a Garage and Parking
Using Summon, once you arrive home and exit Model S or Model X, you can prompt it to do the rest: open your garage door, enter your garage, park itself, and shut down. In the morning, you wake up, walk out the front door, and summon your car. It will open the garage door and come to greet you.
--Tesla Corporate Blog, dated Jan 10, 2016
Despite this being a feature of v7, it actually took an update from the delivery software for the mobile app to work with my car. Lately, it hasn't been living-up to the promise either. It isn't consistently opening the garage door let alone parking itself; today, my Model X, Pensive, wouldn't even show me an image from the rear-view camera making old-fashioned driver-parking an adventure as well. Parking a Model X with just the side mirrors isn't the most fun, but I'm getting pretty decent at it.
Summon: your parked car will come find you anywhere in a parking lot. Really.
--Tesla Model X Configurator, retrieved May 10, 2019
Tesla added this snippet to their order configurator earlier this year (around the announcement of the $35k Model 3 if I recall correctly), but I've yet to even see a mention of it in the release notes or documentation. Apparently Elon promised last October, that an enhanced version of Summon which could read signs and park itself would be available by Christmas; what resulted in March was a limited Beta that was essentially a version of summon which supported longer travel distance and turns.