I think it's just a majority of women and not all of them because I'm sure women like Cars don't focus on the pretty model when watching car commercials. The thing is that mass marketing often has to focus on the lowest common denominator aka the majority of a targeted population that doesn't think twice when looking at ads and thus is very susceptible to unconscious influence. Which leads to why car commercials look the way that you've described them; they've targeted consumers in a highly stereotyped manner in order to capture the most interest from those groups. I'm not disagreeing with you btw.