Hi iphi, I'm heading to UWM this fall too! Have you tried padmapper? That's what I've been using to gauge prices in different locations. I've seen a few places on there that offer parking, but not many. I'm thinking of going in mid May to look at places, which I hope isn't too early to start looking for an August move in. I'll probably have to live alone, because my cats are little demons, sigh.
You might also want to consider AmeriCorps NCCC, where you'd get to travel and volunteer with a small stipend. If you complete the program, you get an education award of about $5000. I did the VISTA program which is more on the administrative side, but everyone I've talked to who did NCCC loved it.