Crashing a car is generally not the most economical use ... and then you're on a Salvage title anyway, who'd keep it?.
Do you know how I know you didn't watch the video before you commented? Because he addresses all that. Since you probably still won't watch it, I'll recap from memory
- steel chassis cars -- $6-8/lb
- aluminum chassis cars -- $20/lb
- box w/ McPherson struts hits the ceiling ~2000lb
- full size station wagon w/ in-wheel suspension would get 60mpg
- low weight through reduced parts count.
There is no reason for the weight to balloon to 2000lbs. It's not a minimalist econobox, it's a race car.