I entertained the idea of commuting out of Raleigh. The port authority there are apparently "parking nazi's". To get a permit, you must live within a certain county radius of the RDU airport, with proof such as a utility bill with your name on it (Greensboro is not even close enough), and have a NC drivers license. When this is done it takes 2 - 3 weeks to process the paperwork and get your permit.
You can park at a certain area of the parking lot, which is in another time zone, for 4 dollars a day without the permit. This particular lot is useful only if you drive a rickshaw or a Vespa scooter because I understand the lot is always full and they are not shy to give out tickets. I wish I had better news for ya. good Luck.