I was not happy with the return process. Maybe it’s because I have an Italian driver’s license, but picking up the car wasn’t an issue. Just firmly refuse when they try to push their insurance, and make sure your credit card has a chip. One time I didn’t have a chipped card, and they forced me to buy their insurance.
Previously, returning the car at their location had always been smooth, but this time it made me furious! The car was parked under a tree, so there were some bird droppings and leaves on it. The inspector kept saying 'too dirty, too dirty!' and told me I had to pay a cleaning fee! I asked if 5 euros would be enough, and he said it would definitely be more. I was so angry right then!
I said, isn’t it normal for the car to get dirty when driving? Don’t you clean it before handing it over to the next customer? He pointed to the dust on the car and said that kind of dirt was acceptable. I was so frustrated!
Then I took out a bottle of leftover mineral water, poured it on the car, and used some tissues to wipe it! Even the shuttle bus driver nearby couldn’t stand it. After I wiped it twice, the inspector finally said 'va bene, va bene,' meaning it was fine.
I just wanted to write this to remind everyone: pay for what you’re supposed to, but don’t give them a cent more than necessary!

There were hidden charges, and I was additionally charged for car cleaning.

Actually, there is no Surprise rental car. The actual rental company is Autoone; Surprise is just a brand name. There are three receptionists during the day, and the procedures are quite extensive. They kept recommending the very expensive full insurance. The car was not the small one we wanted, but a compact Opel Astra, and there was no explanation for the change. When picking up the car, no one inspected it with us. They just said to take photos of any issues for records. There was a notice at the front desk that there would be a €22 cleaning fee if the car was not returned clean, which was not mentioned on the rental platform. A €900 deposit pre-authorization was required. When returning the car, there were no issues found, and I requested the deposit hold to be released immediately. The staff agreed and operated the computer to send an electronic receipt. However, the deposit was still not released even after I returned home more than half a month ago; I don't know the reason.

That wanted to sell their insurance too much. Even though I said that I already have a full cover from Qeeq, they've been saying that it won't cover anything so I have to get theirs.

No chance to refuse extra insurance Had to pay twice!