What should i do? carseat installation?? please please answer?

It is a scientific fact that the driver will react faster to impending issues on her side of the car. Even if your mind tries to tell you to save the penger side in an accident...your body usually reacts to your side of the vehicle. It is very safe to have your son on your side in the back. I can see why you say middle...because he's not easily impacted from either side...but next best is behind you. (only problem is you can't see him easily if you have a baby mirror)