That’s a lot! He will have a very hard time choosing later which ones to say no to 
At U Michigan, my son said that there’s a big check-in table in the lobby of SMTD. It was audition day for many different majors so lots of students. There were seats in the lobby for waiting parents.
There were practice rooms. His audition was in a classroom. Two adults were there, one was the professor whose studio he was applying to.
There were group tours for applicants after audition, not sure if it was on scheduled time or whenever there were enough participants. My son didn’t go on the tour. I guess this kind of tour would be standard practice everywhere.
He waited until all violists were done then they all went to lunch with the professor and some current students, followed by a studio lesson (current students and applicants all attending). Not sure if it was a regular studio lesson or an additional one. Also not sure if the group lunch was regular practice. He was friend with two (then) current students and another applicant so it could be them hanging out then turned into group lunch. During auditions at the other universities he only went to lunch with his friends, not the entire studio.
I dropped him off and went to meet with my friends, then explored Ann Arbor and U Michigan campus. When I went back to pick him up, we explored the SMTD building.
There was a metered parking lot right in front of SMTD. I didn’t pay attention to how full it was when I dropped him off. When I picked him up in the afternoon there were plenty of spaces. We flew home that evening.
I hope this information is useful 