Hmmm, the last issue of the New Yorker has a piece on auto-safety. The key argument is that NHTSA took a wrong approach to automobile safety: it focused on passive devices (such as airbags) instead of educating the driver, which included wearing seat belts. The NHTSA's rationale was exactly as you quote - the frontier, individualistic mentality of most USers would make the idea of safety belt dead on arrival. The subsequent developments proved that assumption wrong, the article argues, as about 2/3 US-ers are now using seat belts a far more effective safety device than the airbag.
Methinks US individualism and frontier mentality is a myth, an urban legend portraying USers what they want to be rather than who they really are. My own observations are that most USeres are sheep (or perhaps "sheeple") in a wolf's skin - they think they are rugged individualists and support that image with symbolic props (SUVs, sports gear, guns, ranch-style homes, cowboy paraphernalia), but in fact they tend to follow the herd more closely than most other nations.
Stanley Milgram's notorious obedience experiments are a case in point. Milgram wanted to demonstrate that USers, as a democratic, individualistic nation, would be more likely than Europeans to extert independent judgment and refuse to follow orders that were plainly wrong. However, in his "obedience experiments" almost every USer uncritically followed orders, thinking that he/she was killing an innocent person. Aomng those few who refused to follow orders were European immigrants.
There is a good reason for that. Individuals are only as strong as the communities in which they live. Weak community and weak social solidarity = weak individuals.
wojtek