Always make your reservation online ahead of time. (There’s an AAA discount). Come as early as you can if you’re leaving your car behind and traveling out of DFW; the vans and busses get full fast.
Call the shuttle while you're waiting for your bags. If you only have carry-on then call as you walk off the plane. The shuttle will be waiting for you!
DFW airport does not allow PNF to pick up anywhere other than the "gray courtesy van signs" they're always on the lower level of the terminals. You have to find them or PNF can't pick you up.
You have to call park n fly, and wait at least 30 minutes standing in the heat or cold with your luggage. Meanwhile 5-6 parking spot vans have passed by....