I was really skeptical to rent from Sixt after reading the reviews from PHX airport, so I chose the Scottsdale location and hoped for the best although I knew the selection wouldn't be as great. The prices were actually way more reasonable at the Scottsdale location. I requested a Mercedes SUV. There is an option for a note during the reservation and I made it clear that I was not interested in a Volvo, which they put in the same class as a Mercedes. I attempted to call a few days in advance to speak to someone at the branch and it is literally impossible to connect with someone at the actual branch. All the calls get routed to corporate. They state there is no way to check in advance of what car you might get, and 30 min before your reservation you will be able to choose on the app. About an hour before my reservation time, the local branch called me and let me know they didn't have a Mercedes SUV in the class I chose, but I could upgrade for another $35 a day along with a bigger deposit. I wasn't interested in that so I asked what other options their were. The agent was able to get me into a Range Rover Evoque but I still had to pay the upgrade fee of $20/day. The car itself was really nice. Easy to drive. Smooth to drive. I took it on a road trip to Vegas so the unlimited miles feature was great. My major complaint is that the vehicle was not very clean on the outside. This was a luxury car and I expected it to be CLEAN. The rims were filthy and filled with breakdust. There was still adhesive on the rims likely from the car being newly delivered (had 8k miles when I picked it up). They stated they didn't have a car wash and "it rained", "it's dusty"....like yeah we live in Arizona. I ended up taking the car myself to the car wash and spent another $40 for a full wash including the rims. There was a few minor dings that I made sure they documented prior to me leaving the pickup location. I brought the car back cleaner than they rented it to me for. I was told by the agent that the manager would apply a discount to my final invoice, but that never happened. If I'm in the market for a luxury car, I would probably rent from here again but the lack of cleanliness of the outside of the car was a major turn off.
***Update: They did contact me and adjusted my invoice to reflect the discount. Thank you.