What to do with large open ceiling space

My garage is 40' deep X 60' wide X 20' tall. There is a 40' X 20' mezzanine (full second floor).

That basically leaves me with a 40X40X20 cube. This area is mostly for working on cars and such.

Anyone have any creative ideas on how to utilize the upper large empty space for anything?

It's this upper area here I'm mainly talking about.