Who do you fly for? If you aren't based at DFW you'll have to get a non based flight crew form for parking from your airlines base supervisor. Parking is $50 a month and you buy it quarterly.

Other options include: Calling hotels and asking them if they will let you park there or the Belt Line Rd station for DART. They let you leave your car there long term at your discretion, all you pay is the $2.50 for the rail pass.