Self-driving 3500KM in Germany, Austria, Italy

Arriving in Frankfurt full of enthusiasm, I had to walk quite a distance to collect the car, which was a C4 Cactus with a 1.2L gasoline automatic transmission. I had to find it myself in the parking basement. The car had only 8900KM but felt old and small. Upon inspection, I found damage on the side mirrors and hood, suggesting I was being scammed. I immediately reported it and got a yellow tag for the damage. Driving on the German autobahn was a disaster, as the car roared at full throttle for thousands of kilometers over 21 days and couldn't easily overtake other vehicles. It felt like a gardening vehicle suited for an old Frenchman in the countryside. The 1.2L engine lacked torque, making it impossible to climb even small slopes in parking garages. I nearly hit cars multiple times when the car rolled back during refueling. Thankfully, with 20 years of driving experience, I used the handbrake technique to manage. Choosing Frankfurt as an entry point turned out to be a mistake. The rear windows couldn't open, making it very unsafe, especially for female drivers. This car rental was the worst part of our one-month European trip, despite the beautiful scenery and nice hotels. Avoid believing the big companies' promises and free upgrades; Hertz gave me the worst car, and using QEEQ was just a waste of time and money.