Are our Slants "Unsafe"?

One of the safest types of cars are mid 70's fullsize luxory barges.

Agree. For a time, maybe 1973 to 1978, new cars had to pass a higher impact standard - 15 mph into a solid wall w/ no damage, I recall. They did this by making the front bumper supports serve as impact absorbers. That is why they look ugly with the extended front bumper, but it worked. The main reason was to decrease growing repair costs, plus increased safety. That only helps if you run into something (idiot driver). The Pinto was good for that, but not for rear impacts (other idiots). The law was dropped. Many opinions on why - lobbying by manufacturers and/or body shops.

New cars have done a lot to design-in crumple zones for front and rear impact, but have done little for side impacts. I would much rather be in my 65 Newport 4 door in a side collision (have been) than a new car with thin doors. They did add a side brace and side air bags to the latest cars, but minor help. There is a reason that demolition derby drivers like the Chrysler C-bodies.

What injures or kills passengers is - deceleration, protrusion of objects like the steering shaft, and impact with the interior. Crumple zones and absorbers decrease the acceleration, but being in a massive vehicle is best for impacts with other vehicles. However, we can't all drive dump trucks. The protrusion issue was helped by collapsible steering columns (~1968?) and transverse engines. Impacting the interior was helped by padded dashes and softer steering wheels, however that is an issue only if the driver is too stupid to wear seat and shoulder belts.