I guess we could start another thread if we want to discuss monocoque-type construction (which has been going on for decades in racing) and now some production cars. But that is taking the design of the ENTIRE car into consideration. That entails some heavy number crunching for sure regarding; strength, weight, cost, etc.
The original poster asked about aluminum, BOLT-IN roll bars and I gave my opinion. If it's for your street car and you want to build one out of elbow macaroni and spaghetti, welded together with hot droplets of water - I encourage you to go for it!
Just don't try to take it to the track and pass tech.
