I like Sixt in Denver and use it often for my monthly visits. I was last there on April 25 2023 where I rented a BMW x5. PERSONNEL: The checkout process was pretty smooth, as usual. The agent who helped me was Elizabeth. She was wonderful, friendly, and helpful. However, the first agent I went to that day was Krystal, who was not so good. She was sitting at her desk just staring off into the distance, not interacting with customers. She didn't acknowledge me when I approached the desk. She said very quietly that she wanted my license and credit card, which I gave her. She had a very bad attitude. She was so quiet that I couldn't hear her. I stopped interacting with her and moved over to Elizabeth's desk, where all went well. VEHICLE: The car that I picked up had a few maintenence problems: Within 60 miles of driving, it alerted me that it needed a quart of engine oil, which I stopped, purchased, and added at my own expense. It then kept alerting me to a need for a "software update." It seems like Sixt maintenence could have caught those items before giving the car to me. The car has several automated features. One was an attempt to keep the car within the driving lane. It would actually turn the steering wheel to do this. Unfortunately, it tried to do this in construction zones where lane definitions were wanting, and on narrow mountain roads where there often were no lane lines. This resulted in me needing to "fight" the steering inputs, a safety problem. The car's owner's manual was over 400 pages long. The first night I was traveling I took it into my hotel and researched how to shut off that feature. In fact, there are several unusual behaviors programmed into the car. Based on my rental experience, I would never buy a BMW x5. It would be helpful if Sixt (or BMW) would provide a single-page guide for just the most intrusive "features" so that I can set them when I pick up the car. WEB SITE / APP: One other observation is that the Sixt web site does not have any way for me to communicate compliments about the staff, complaints, and concerns about the car. Overall, I like Sixt, but would like to see some improvements.