ALL IS RIGHT WITH THE WORLD
Fair warning, parking prices are considerably higher than they were over the last few years. Lots that are often $15-$20 to park, were doubled (at least) for the MSU/Michigan game, even those well over a mile away.
I park at a parking garage on Ann, off Main st, downtown. It's $3. However, the day of the MSU game, they took payment as people were leaving the garage, which resulted in a long backup and us being stuck in there (parked on 4th level) for over an hour. I recommend getting there early and securing a lower level spot, as the trip back to Dayton (in my case) is already long enough.