Janine at the Sixt Station in Köln Porz/Gremberghoven is fantastic. We often need hire cars at short notice, and most other stations in the area have shortages at the moment. Janine, always manages to help us out. We sometimes have to change, rebook or leave the car at a different station, and all of this is never a problem. Can not recommend highly enough! Use this station if you need a car, you won't find a more professional or friendly car hire in the Köln/Bonn area.