Parking on campus can either be a hassle or relatively stress-free. It all comes down to how much you are willing to pay. Permits for the most reliable places can get pricey, as you are paying for the guarantee of finding a parking space. Some students go the route where they try to get by without a permit, to try and find parking where they can, either for free or when Parking & Transportation Services isn't keeping a close eye on the area. Usually, this backfires, and it is extremely hard to avoid parking tickets or the dreaded boot for your tire.
Carnegie Mellon makes it pretty unnecessary to have a car during your time in Pittsburgh, unless you need to make frequent trips outside of the city and surrounding neighborhood limits. CMU student ID cards have an icon on them that lets students use the Port Authority buses at any time, free of any extra charge (it's incorporated into tuition and fees). Bringing a car to campus and paying for either a permit, or the equivalent of a permit in parking tickets, just seems like a waste. Students often complain that the University "nickel and dimes" students for services, and paying for parking is usually the loudest complaint of all.