The car was quite dirty, and there was a lot of sticky residue on the side door.

No suitable cars available. Comparing a VW Golf to BMW, Mercedes, or Audi is unreasonable, even internationally.

The reserved car was not available when we arrived at the store. We were given two options: a free upgrade to a Mercedes Benz van or a small manual car. On the narrow streets of Spain, driving the Mercedes van was impossible, and with two large suitcases, we couldn't fit our luggage in the manual car. Essentially, we were given two unusable options. After almost 3 hours of back-and-forth communication, they finally agreed to get a car from another location, and our luggage could barely fit. The car we got was a downgrade (a small Kia), but it only cost us 20 euros less. The entire process was extremely frustrating, and if it weren't for our necessary travel plans, I would have canceled the rental right then and there.

Unfriendly attitude

The model was switched to a Renault wagon, which was smaller but priced the same, plus an additional 21% tax. There was only one automatic car available on-site, no choice given. Either you accept it, or you have no car. Unlike our previous self-driving trips in France and New Zealand where there were upgrade options. So what's the point of booking in advance? It seems the same as not booking at all! We didn't get the model we reserved. Under normal circumstances, a free upgrade should be given, but they just shrugged and said there were no cars available, take it or leave it. We had no choice but to accept it!