I'd be carefull with such statements. I'm a bit involved in vintage racing and rollbars are mandatory for obvious reasons, however every expert will tell you that if you have a rollball fitted to your car you must always wear a helmet (also manadatory in any form of racing). why you might ask? well if you have an accident in a car with a rollbar, the first thing your head is going to hit is actually the rollbar. If that happens and you are not wearing a helmet the resluts can be really ugly, even if your accident happend at fairly low speeds.