Regarding mandatory seat-belt usage, the question is not one of freedom of choice. This is a matter of public health and safety involving the use of motor vehicles on public roads. The use of a motor vehicle is a privilege granted by and regulated by the state. The state may enact whatever laws or regulations regarding the use of a motor vehicle, it deems necessary in the interests of public safety.
I am an auto enthusiast and longtime advocate of the use of seat belts. The lives of myself, my wife, and my son have twice been saved by the use of seat belts/shoulder harnesses. In both cases these were severe accidents in which the vehicle that I was driving was totally wrecked by a drunken driver who had run a red light. Your energies would be better spent trying to eliminate this threat to all of us (drunk drivers) than worrying about the mandatory use of a device that can save your life.
There is no question that seat belts do save lives. In the year after the enactment of Australia's mandatory seat belt/shoulder harness-usage law, the auto accident fatality rate dropped 50%. More recently the state of New York has seen a 25% reduction during the first quarter that their seat-belt law was in effect.