Getting from the East Garage to the Bartos Auditorium in the MIT Media Lab:
Standing in the East Garage parking lot, with your back to the entrance on Main Street, walk all the way to the back of the lot to Building 66 then out to Ames Street to the left.
Cross over Ames Street and enter the Weisner building, otherwise known as the Media Lab or Building E15.
The Bartos Auditorium (E15-054) is on the lower level.