I had no trouble finding the office (it is at Basement level 6), and was informed that we had to wait for a while, while the car was being cleaned. We were offered coffee while waiting, and the staff were friendly. They also informed us that the car we booked (manual) was not available and gave us a free upgrade to another car in the same class, which was an automatic. This was much appreciated. Overall, we had a pleasant ride, and fuss-free collection and return. This was my 3rd time renting from Sixt.