Compelling argument and certainly valid. And I agree 100%.
Still don't think the Gov. should have the power to force it.
Again, caviat with children in the car. Other adults have the power to refuse to ride.
do you kick people out of your car for not wearing their seatbelt? I do.
or I pull off the road till they put it back on.
Would a Gov. mandate on power to weight ratio save lives? Yes. It absolutley would. If they said it's illegal to have anything lower than, say, 15 lbs per horse power it would save lives by taking all the performance cars off the road (let's face it, performance cars cause problems because of the idiot people who disrespect them)
you might want to research that... the statistics for performance car wrecks vs every other car wreck is vastly different. granted theres a smaller population of performance cars out there (depending on your definition of performance), even tho damn near every car rolling off the line these days has at least 300hp in at least one trim level. for us as camaro and performance enthusiasts, it sometimes appears that there are more incidents with performance cars but thats all in your perception.
WGAS if a toyota corolla rear ends a minivan on the interstate?
But if a yellow 5th gen tbones another 5th gen, everybody and their mother knows about it because performance cars stand out more compared to every other car on the road. so when one wrecks, it causes more of a stir.
I dont believe a mandate on power to weight would do anything but abolish the camaro completely. either that, or we'd end up with....
wait for it....
The new 6th Generation Camaro with the "Iron Duke Package!!!" 
some performance cars cause problems because people disrespect them, but more often than not, its the guy in the Tercel with shitty brakes or the mom in the minivan with kids screaming or the girl in her SUV texting that cause the majority of multi-car accidents.
more often than not, performance cars are usually involved individual accidents and dont include others in their mishap.
having a mandate on power to weight would force us all into econobox cars that are lighter and weaker than a lot of the other cars out there.
either that, or manufacturers would be building CTS-V's for everyone (high hp... but high weight as well 
)
think about it this way... more weight nowadays translates easily to better strength and better crash survivability. knock the weight and power down and the roads will be full of ricers. and no one wants that.
My example isnt' perfect but my point is made. (I guess, lol)
Again, I am a seatbelt believer 100%.
My State Trooper freind pretty much made me look at some pics that I don't care to remember but can't forget. And it made me an instant seatbelt wearer. Especially since the damage was straight front hit and at a AI estimated 35 mph.
There are a lot of things that are dangerous that are not illegal. (Yet)
I'm getting dangerously political here aren't I.
WEAR YOUR SEATBELTS!!!!!!!!!!!!!! 
Or Big Brother will BF you.