Right, the study does not compensate for other factors, it's just a fun example of doing number-crunching with blinders on.

 

your car gets f'ed up. It would make more sense to have a car crush like a can as apposed to ramming and holding together like with roll bars. Roll bars would actually increase your chances of getting hurt in a head on collision becuase that car crushing is obsorbing all of the inertia. Cars are getting more heavy I think due to the body styling and overall product quality. In the 80's there was a large oil ressesion that the US had to work around. If you notice all 80's cars look like *** and most of the sedan cars get good gas mileage. I don't know really we need to make all cars with titanium alloy frames and carbon fiber bodies with 500hp w/ 35mpg

 

^^^a roll cage is designed to keep the passenger compartment (and passengers!) intact, not the whole car. you can still have crumple zones in the front and back.

 

The advance to other materials is a slow one. Vehicles in 10 years won't be that different from now because people aren't willing to pay for exotic materials, advanced hybrid designs, etc. They pay for looks, feature content, and size. The latter two contribute heavily (pun intended) to the increasing weight.