We are going on a 6 hour trip this afternoon. I always have my son in the middle of our Durango, but my father in law is with us, so I am going to have to move him outboard for the trip. I usually have in a DC in the Durango, but I also have a regent in the other car. Is one better than the other as far as side impact? There are no side curtain airbags, and I hate the thought of him outboard, but there is no other choice. Which seat would you use? Btw, my son is 4 1/2, about 38 lbs, and 42 inches. Thanks in advance!!