The wheels/tires are the same size as the 1st gen Insight. (Some Insight owners are actually hopeful that the factory LRR Dunlop Enasaves on the Mirage will be good replacements for the Bridgestone RE92's that are discontinued. If I'm not mistaken Mitsu also puts those on its iMiev EV.)
I snapped a pic a week or so back of the first Mirage I've seen parked in the wild, this one sporting a set of winter wheels/tires:
Though I've actually seen 2 others on the highway.
I think this car is a future ecomodding classic.