The rental car facility is located at 1 Nassau Circle, Kansas City, MO 64153. It is on airport property and when you are ready to pick your car up, simply exit the terminal building and cross the street to the median. There you will take a gray shuttle bus (it has all the rental car locals on the side and runs about every 7-10 minutes) to the shared rental car facility.
Facilities are outside the airport. There are shuttles provided. If you are arriving you'll take the shuttle just outside the terminal. If you are leaving drop the vehicle off and they'll take you to the terminal. Allow plenty of time to drop off your vehicle.
I guess that, Mr. CE Lopez comment is helpful.
Sorry I have never rented a car at the Kansas City Airport
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