Here's the lowdown on the SIPS. The SIPS system involved a few reinforcing bars as well as the side air bag built into the seat. Volvo beleives it is better (and I agree) to have it tin the seat as no matter where the seat is the bag is in the right place. One measure has been shown is the lengthening of the B pillar toward the front. This is to allow the bar built into the seat bottom to meet up with the B pillar if it is pushed in. Also there is another bar across the roof running just behind the sunroof. If you want to see what it looks like find an S70 or 850 without a sunroof and it is in the bump in the roof across the top of the B pillars. There are also two more reinforcing bars built into the floor of the car and if you really want to see those take out the seats and all the carpeting. You may not be able to see them because there is a double floor in that area as well. As well as all this there is still the steel bar in the door itself but that has been there since the 1976 240. I don't beleive they were there in the 1975 and earlier cars but I could be wrong.