How do I return my rental car after hours at the SeaTac Rental Car Facility, and what are the procedures for using the SIXT key drop box?

At a glance

To return your rental car after hours, proceed to the designated key drop box area at the SeaTac Rental Car Facility, located at 18200 International Blvd, SeaTac, WA 98188. Follow the locking procedures and use the SIXT key drop box.