You are much safer in a 1964 Chevy, even without your seatbelt on, than you are in any car built today.
I'm not so sure about that, Joe. Crumple zones, impact absorbing and dispersal technology and other advances, many developed from racing technologies, have really played havoc with the size/safety equation. A case in point...
A few years ago my best friend was involved in a near head on collision at about 60mph. An oncoming driver and he were both stradling the centerline of a two lane highway and the opposing front ends made contact about one third of the way across the hood widths. He was wearing a seatbelt and the only injury he received was shoulder "burns" from the belt when it tensed. He walked away and called for help...the other car was a large Ford, and the people in it didn't fare as well (only driver wearing seat belts). Both cars were utterly totalled.
He was diving a Honda hatchback. The engine, doing as it was designed to, dove down and the front end of the car effectively disintegrated dispersing the energy of the impact. The cockpit was undamaged.
I've had friends go through the windscreen of cars while not wearing seatbelts (impact with a traffic divider on an Illinois freeway..fell asleep). Belts and airbags can save your life (but relying on the bag without the belt is really foolish). A few years my new Chev Cavalier two-door had an encounter with an unliscensed driver who ran a red light at high speed and tried to take the front end off. Tires flying (theyre supposed to in that case) and body parts (the car's) everywhere. Didn't even deploy my air bag and everyone got out and stood stunned at how much damage was done to the various cars involved (he bounced off me and hit someone else) yet not even minor injuries.
I remember cars from the 60's. Yes they were big and heavy, but mass and metal don't always return greater safety. Some, admittedlty when you're the bigger car in the accident, but not always.
All that being said, yes, if I have a choice between being in an accident in a Suburban vs a Geo Metro, I'll take the truck. But pound for pound modern cars are much safer in a collision when there is some hope of survival.
You really want safe? Buy a Mercedes 600 sedan. A german banker was blown up in one in Berlin a few years ago by a bomb placed under the back seat. Driver lived (damage confined to the rear). Also note that if Diana and Dodi had been wearing their seat belts there's a better than reasonable chance they would have survived. Injured severely, yes, but alive.
As an aside, think of the fatality rates in Formula 1 racing prior to the safety regs that came in after Senna was killed. Some of the crashes today would routinely result in terrible injuries in those older cars. Again, impact energy dispersion and controlled crumple points.
Cheers and safe driving, eh!