I'm planning a trip to Dallas and I need to drop off my rental before 6:00 am. Is someone there before 6:00 am ? Cause I will be looking to drop the vehicle around 4:30-5:00 am

Upstairs National/Alamo/Enterprise returns...put keys in drop box please...DFW AIRPORT

Let them know as you pick up your car and there's a drop off place for the keys when you get back in.

Yes you can just verify when picking up.