What it says is that the government tests (at least in some ways) are crap.
A civic May test better for a front end collision than a 5000 lb 90s Benz sedan or Volvo ... I really don't know for sure BUT I strongly believe if your wife was to be rear ended or side swiped by a Suburban that she would be far better off in the 5000 lb 90s Benz just because of the pure physics of the cars involved.
What the government tests do (in order to make small cars appear safe) is test the vehicle (eg a civic) driving into a cement block but they don't test a cement block equal to a suburban driving into a civic. As I mentioned before these are two very different things and the government tests don't really reflect that because if they did then these small cars would all have bad ratings.
First, I think that you entirely missed the point of my post.
Next 5000 is a monster of a car, even today. It's really only the realm of SUVs. The big Benz in 1990 was pushing 4000lbs, and I referred to a midsized car. I was thinking of a 3 series or 190E, and at about 2800 lbs, they are about the size of a modern Civic or Corolla. For giggles a 1990 5 series is about the size & weight of a new Accord.
Now, I love my old BMWs, but a 90 3 series or 5 series won't match up in safety to newer econoboxes. Crumple zone design and improved safety cages, along with better airbags (including many more per car) are making cars much safer. I have an 88 3 series & an 06, and there are light years in between.
Side swipes & rear ends aren't the kind of accidents you should be worried about. As I mentioned, you're worried about high speed differentials, like head-on shots & t-bone collisions. The others damage cars, but generally don't result in injuries. Side airbags, crash bars and other side reinforcements have drastically reduced the number of deaths in t-bones. Offset crash testing changed the ways cars were designed.
Many of the crash testing methods were developed within the industry. The IIHS pioneered a lot of methods used by governments today. The popular offset frontal crash represents one of the most deadly types of crash, and one of the most common: a car running off:mullet: the road into a stationary object with a glancing blow.
Crash safety is about destroying the car to dissipate energy to save the occupants, and modern cars are so much better than in the past. Traffic deaths are at an all time low, and based on my experience, it's not because people are such good drivers. Cars are getting better at helping to avoid crashes and performing much better in the event of one.
I still pick a well-engineered mid-sized, luxury sedan, wagon or crossover over most anything.