Which place is the safest for the third child?

Hello, After the birth of our third child, we want to buy a new car and I have a question that should be asked frequently, but unfortunately I find the concrete answer neither here, nor in other forums. Most sources agree that in case of an accident the safest places for the first two children are left and right in the second row, best in child seats with isofix. However, it is not clear to me which place is the safest for the third child – en r passenger seat (with airbag on or off?), the middle seat in the second row (it is not considered to be particularly safe anyway), or a seat in the third row? For longer rides we will prefer that an adult sits between the two smaller children in the rear. Where should the oldest child (7 years old) sit most safely – on the passenger seat in the front (with airbag on or off?) or in the third row? To get in/out and drive is the passenger seat But what is safer for the child in the event of an accident? Is there even test results that compared the different seats for children? I did not find any. Personal practical experiences from everyday life with three small children would also be very valuable! This question is very important for the choice of the new car, to decide whether it should necessarily have seats in the third row or not; that the driver should have seats in the third row. It has other advantages to me, but the offer compared with 5-seater is much shorter and often much more expensive. Thanks in advance for your help and tips!