What is the right thing to do?

In this scenario, the correct action is to yield to the green car. According to German traffic rules, when approaching an intersection or any situation where right of way applies, you must yield to vehicles that have the right of way, which is often indicated by traffic signs or lights.

By giving way to the green car, you ensure safe traffic flow and prevent possible accidents. Additionally, if there are vehicles coming from the left, like the red car, they may also need to be considered if you are turning left. Understanding right-of-way rules is crucial for maintaining the safety and efficiency of traffic.

In summary, always yield to vehicles that are either on your right or have the priority according to traffic regulations, and ensure you have a clear view of any other approaching vehicles before proceeding.