Tiag is 100% correct. during a frontal offset impact, (as well as many other types of impact) the passenger cage must withstand the structural damage by deflecting the kinetic energy produced by crush.. this is achieved by absorbing the energy by the components surrounding the passenger cage and somewhat controlled manner, when certain parts of the body deform (thus, absorb the energy) in a specific fashion (thus deflecting the vector of force) that the rescuers see a mangled pile of metal, and live people emerging from it... take a look at the inner parts of the fender, where they attach to the unibody - you will see that the metal is fashioned with some "dimples", or "creases", that will fold in case of impact...

I am not saying that the other bolts will drastically change the results of a crush, but I am not the one willing to test the theory...

I had posted a few years ago a crush test results from a test of chinese made knock-off of a german Opel (ithink it was Chery Amulet) - the results of the test were devastating, the dummies were mangled to the point that they had to be pulled out piece by piece, while the original german car was fine with the TUV tests (or whatever the test authority in EC is)... of course the chinese knock-off was priced in the vicinity of $8-12 K brand new, while the original was much more expensive...