It wasn't Buchbinder (they were bought by Europcar?). Be careful in the return process because they will "find" you an invisible scratch that you will never be able to trace (like under the baggage hood) to charge you for handling and fixing fees.

Anything was perfect.

Overall, it was okay. The car was new, having just over 10,000 kilometers on it. The vehicle was in good condition. However, the customer service insisted on adding insurance when we picked up the car. We initially chose the secondary insurance, but they said German roads are narrow and that even if we didn't hit someone, others might hit us. We had to add an extra €198 for insurance. They also recommended more expensive cars like BMW, even though we repeatedly declined. This was quite uncomfortable. The car pickup process took almost two hours, likely because the rental company is small. It might be considered big in Germany. Returning the car took a long time as well since it was hard to find the return location. Most major rental companies are at the train station, but this company's prices were reasonable. In the US, we never encounter such issues. After landing, rental companies are inside the airport, and you can get the car quickly. Germany's process is slightly more complicated. However, returning the car was quick. After handing over the keys, they checked the car inside and out, including the fuel. It was a fast process. Thumbs up for that.

The attitude of this company is extremely bad. They do not accept magnetic stripe credit cards and do not inform upfront. I purchased full insurance, but they still charged me 1200 euros as a deposit. They also charge 45 euros for cross-border service, very greedy. I tried to negotiate with the rental platform for a refund, and it's been 7 days without any response. Later, I went to HERZ and was very satisfied. A 9-seater Mercedes for less than 400 euros for 3 days with full insurance, with a prepaid fuel charge of a bit more than 200 euros. When returning the car, the inspection staff falsely claimed that 45 euros of fuel was missing, even though the tank was full. I went to the HERZ counter, showed my refueling receipt which confirmed a full tank, and they said I had done the right thing and would verify it at the counter.

It's okay. The rental company tried to sell us their full insurance, we didn't agree at first, but the staff didn't push much. Everything went smoothly.

The Mercedes Viano we originally requested was swapped for a Volkswagen Multivan. It drives like a bus, incredibly noisy and has horrible sound insulation! It's extremely uncomfortable to sit in. The front layout is like a truck with a two-seater next to the driver's seat, and the rear seats cannot be adjusted. There's no storage space at all, and we couldn’t even figure out where to put a cup of water. They claimed it was an upgrade, which is ridiculous! I will never use this rental company again. We spent over 10,000 on this trip and were expecting the comfort of a Mercedes, but ended up with nothing! Terrible!