On paper a newer (yet similarly) sized car will yeild better passenger comfort when in an accident however realisitically this I've found, though my observations, that is is not necessarily true.
Obviously without airbags and ABS brakes you are behind the times however ABS brakes, in my opinion, are for people who don't know how to drive a car. Also, IMO, airbags are being used in cars to supplement (NOT COMPLIMENT) the safety of the car.
If the kids will be driving the car, or the wife isn't that good behind the wheel...then maybe a new car is in order. But if its you behind the wheel, purchasing a new auto will simply put another monthy leech in your wallet eating up money you might be otherwise spending on something for your family that wasn't pseudo safe.
I drive my w126 body and its the only car I feel safe in while doing high speeds. I've seen how they perform in crashes and have a very decent idea of my surviviability rate. Given it has no ABS, no airbags, not even limited slip.
But I can tell you for a fact that if I had HAD ABS brakes...my car would be totaled right now. If I had airbags...I'd have them pop if my face at the wrong moment and cause me more harm than would have otherwise taken place.
WHen you car is doing a 360 on a straight but rivine sided icy road...you'll enjoy every moment of fully locked up brakes as the car travels straight down the road...sideways..backwards...sideways...and then forwards again.
Just my thoughts...seatbelts + intelligent driver is going to win over a middle of the road new car for now.