Everyone has the gameday plan of pulling in the car, pulling out the grill, and tailgating until gametime. Sometimes the unique parking situations at UNC make that impossible. If your friends already have a tailgate spot, consider the Tar Heel Express shuttle which allows you to park further out and shuttle into campus. The round trip cost is $5 and one-way is $3. (During basketball season there is also a route from the Carolina Coffee Shop to the Smith Center which is $2 one-way and $4 round trip.)
Service to and from the University Mall, Friday Center, and the Martin Luther King Blvd lots start 3 hours before game time. Buses from the Southern Village and Jones Ferry lots begin 1.5 hours before kickoff.

For more info on gameday parking at UNC refer to this great packet put out by the UNC Department of Public Safety (aka Dept of Will Tow and Ticket Your Butt).