Frosty5, you simplificate too much, nothing wrong with HMC 's rules to retain the 15" tires, iron heads of the era... but then to suggest that all those cars should have a ~2013 compliant roll cage ... sounds like you want a foot in each camp, I have a problem with the current cage spec, it virtually requires a Hans device to make it safe, if you dont have the Hans device the chances are you will be KO'ed when your head clouts the longtitudinal bars in any sort of side impact, this is in my mind one of the major problems when fitting a current cage design into an older car, especially the smaller Euro, UK designs which have smaller/narrower interiors. A roll bar should be just that, a structure to prevent the roof collapsing in the event you roll the car, I think this would be enough for most classic type cars, the 'Cage' builds too many variables into the car in terms of stiffening the chassis, adding weight, inhibiting access etc.

PS, I shudder at the thought/vision of a cage designed by a 'legal eagle' [ ever noticed that both words use the same letters? ]