How'd you reinforce the lug inside the body that the spring seats on? That's the only real failure point... have the bolt barrel and a paintball going down the feild... id actually pay to see it.
This brings to mind a Honda I once saw; 2 inches off the ground, carbonfiber doors, wheels, roof, hood, and spoiler. Easily $20,000 in carbonfiber to knock off a maybe 75lb. Then it parked, and the two 6'3" 350lb Samoan guys got out.
Still, really cool. I like the look, time to cap that valve and get a UL'ed rail though!