Old thread, but worth bumping in case others come across it in the future.

Sixt does have its own office in the garage, but you are assigned the car inside the terminal office. The parking deck office just gives you the key and does the walkaround with you. Maggiore shares some of the garage space with SIXT on that side of the parking deck iirc. Hertz and the others are on the opposite side.

Reserved - and received - IDMR, Alfa Romeo Giulietta Diesel w/Nav. It looked like upgrades were available (for example, there was a whole row of Mercedes GLK's there) but was told no upgrades of any kind were available, which was disappointing. They had tons of other options available, most of which had navigation. The pickup process was fairly painless, waited in a short line at the terminal office, got the contract, went out to the parking deck with the contract, did a thorough walkaround and noted all damage at time of pickup. I dropped off after hours before the station opened around 4:00 AM and had no problems; CC charge came through a few days later and all was correct. For personal piece of mind I took pictures and did a full video walkaround of the car (including fuel gauge and odometer) upon drop off given horror stories of phony damage and fuel claims, but thankfully did not need to use any of them.

Word to returning renters: Keep in mind there are very few gas stations in the immediate area of the MXP airport, even fewer that are open late at night. None of those that were open would take my American CC at the pump, so had to pay with cash. BE SURE TO HAVE ENOUGH CASH!

The car was pretty new, clean, and most importantly smoke free, but other than the standalone Nav option, it was totally bare bones. Fortunately, the Nav could be programmed into English. It did not have Bluetooth, USB or an Aux-in jack for an iPod, so it was Italian terrestrial radio for us. It had power locks, windows, and thankfully, cruise control, but that was about it. Oh, and it did not have any washer fluid in it at pickup either; had to buy a bottle on the road, but given that the office was closed when we dropped off, could not get reimbursed for it. Oh well!