The shuttle departures every 15 minutes.
Shuttle tracker, to see exactly where the bus is: www.sixt.is/shuttlebus
To find the shuttle:
Walking to our Keflavik branch, Blikavöllum:
Sixt branch in Reykjavík is at Fiskislóð 18, 101 Reykjavík.
Your key to the fast lane - skip the queues and the rental formalities.
All you need to know about bookings for vehicles by SIXT.