Don't know if you've found an answer yet.. but I'm an undergrad in Rochester, and I bet you're right. There's absolutely NO parking downtown. I have a spot at a downtown ramp only because I live in the undergrad apartments.. when I was registering for my card at the parking office, I heard of the guy next to me getting his card after 13 YEARS on the waiting list..
i think your best bet is finding a place to live within walking distance..]
then again, there are mayo designated parking lots miles from downtown that have a free shuttle to the campus.