Contemporary cars, and light general aircraft, have had 40+ years of research into human impact tolerance, and modulate the crash forces to the driver + pax bodies. You are MUCH safer in a crash in any modern car, regardless of size, than in our beloved MOPARS. A break point is 68, the year the Feds required some energy absorption, dual braking systems, etc. Next time you are at Pick n Pull, or your favorite parts yard, look at crashed cars: you will see intact passenger space, and completely deformed front ends...the force that formerly would fracture your sternum, bruise your heart (YES!),or contuse (fancy word for bruise) your brain has been turned into friction of bending metal. Rigid bumper, rigid steering column = max force to your body. ASAP, i shall install shoulder belts in my 63 SF vert, as we did in our Piper Commanche. Easier in the Piper though...! And, consider the "packaging" of the human race driver body: Dale E would have survived his 150 mph crash if he had a HANS, to protect his spinal cord and neck. Suddenly HANS became mandatory in NASCAR. Formula 1 cockpits are molded carbon fibre inserts, produced from a mold of the driver's body. All for survival. Our cars will be lethal in a crash, even with seat belts. But, the main protection is shoulder belts, VERY tight, no inertia reel (which allows slack and contact with the steering wheel ) Airbags add little, if any, modulation of energy to your suddenly very scared body....! Invest in shoulder belts, and drive free of worry...well, almost...