You want to overtake the vehicle driving up ahead of you. What is necessary to allow you to do so?

Your answer is fully correct because all three conditions are essential for safely overtaking another vehicle according to German traffic rules.

First, you must considerably increase your speed to pass the vehicle efficiently and avoid obstructing traffic. Second, using your indicator (turn signal) is mandatory to inform other road users of your intention to change lanes or overtake, which enhances safety and prevents misunderstandings. Third, observing traffic to the rear and side is crucial to ensure that the adjacent lane is clear and there are no faster vehicles overtaking you, preventing collisions.

Together, these steps help you perform overtaking maneuvers responsibly and in compliance with the German "Rechtsfahrgebot" and general traffic safety principles.