Picked up the car at Barcelona T1. Waited in line for about 15 minutes. The customer service representative was very friendly and although they did try to sell additional insurance, they weren't pushy. Just say no if you don't need it. The car pickup was in the underground garage, simply take the keys and go. Returns are at the same location as the pick-up. The parking lot is next to Area A. Make sure not to park in the wrong lot, or you will have to pay. Although there was only one person checking the returned cars, the process was quite fast, taking roughly 10 minutes per car.

Due to communication issues, I only needed an additional driver insurance, but the rental company charged me for comprehensive insurance, resulting in double charges of 773.45 euros. I had previously chosen the super supplemental insurance with my booking on the rental platform, meaning I wouldn't need to pay any extra fees in case of any issues. I couldn't contact the rental platform while abroad, and I am currently resolving the issue with them after returning home.

Arrived after midnight. The rental company had already added many items to the contract. I did an electronic signature on the computer without even receiving a detailed list, which caused issues.

Pretty good, but their English isn't great, hard to understand.

The Avis counter staff at Barcelona airport said that I don't need to refuel the car, claiming that the company's fuel charges are the same as the gas stations. I used less than half a tank and didn't refuel before returning the car, but later I was charged for a full tank. This staff member seriously misled me about the fuel price and refueling rules, avoiding the important details, which is completely fraudulent.