Convenient

Probably won't consider AVIS again. They charged an extra driver fee when picking up the car but since we forgot the proof, they deducted another fee when returning it. They were also very uncooperative and had a bad attitude regarding fines incurred during the rental period.

The service reservation phone number was unreachable; I don't understand why there was an error in the contract that restricted our self-drive to Germany only; Zuzuche should clearly state the precautions (e.g., payment methods and actual procedures are different, return signs...).

Good, but they tried to sell me extra insurance.

A very good car rental company. Picked up the car at Munich Airport according to the directions in the comments. The service was provided by a sweet girl dressed in traditional Bavarian attire. You need to go to the parking lot and find the car based on the parking space number. The car was very clean inside and out. The only issue was not hearing clearly about a small parking ticket needed to leave the lot, resulting in an awkward delay at the exit.