Muir Hall exists as overflow housing for the main building. Residents of Muir Hall must be over the age of eighteen.
The garage has multiple levels, with just one level above ground. School owned vehicles are kept on the top level, with personal vehicles assigned parking spots on lower levels. The auto shop (the non-secret one) is also located in Muir Hall, on the first floor. Don't worry, residents, the shop area is very thoroughly sound-proofed.
Similarly, the bedrooms and common areas in Muir Hall are also sound-proofed and very well reinforced, as the building was built specifically to house mutants with various powers. So feel free to have your death metal band rehearse at 1am. Nobody will hear.