I have to say that using a seat belt is still the best way. Most accidents are not rollovers but two vehicles running into each other one way or another or into something stationary. I have lap belts so far but will be converting to a lap shoulder harness before the car is on the road. Most of the time I want to stay with the car, not be tossed around, i.e. through the windshield, impaled on my shifter or e-brake lever or rolled over either by the cars' wheels or the 18 wheel semi following too close on the freeway or as the car goes shiny side down. Yes, you are taking a small chance if the car goes over, but that chance is a whole lot less then being thrown out.

If you think you can hold yourself behind the wheel, then just watch a vehicle test with a real world car, not one of our '30s style street rods that have virtually no safety features like crush zones and air bags. These are on You Tube - and those tests are at 35MPH. You can't hold yourself - G forces are a lot stronger then any of us!!!

http://www.youtube.com/watch?v=Gjp7dFnuU4c

Another just for consideration, and probably a lot closer to our '30s cars:

http://www.youtube.com/watch?v=ju6t-yyoU8s