I dislike overweight behemoths as much as any cyclist of pedestrian would, but neither masculinity or individualism have much to do with it. Arguably cycling is more individualistic than driving an automobile. As for masculinity, if you were saying that about muscle cars, yeah, ok; maybe -afterall men get accused of buying those to compensate for lost masculinity. But anyway women like SUVs as much as men (women buy more SUVs, men buy more light trucks). No surprise they’re called hausfrauenpanzer.
Let's say collectivism is the opposite of individualism, so if I was to take a collectivist mindset about my car choice something I might consider would be making sure I can see the other people in my community well while driving (because cars are dangerous) and I don't want to hurt someone. I'd argue that the opposite of that choice would be to buy a larger vehicle which makes me more safe at the expense of other people, by making them harder to see and hurting people more because of vehicle mass.
As for masculinity, anyone regardless of their gender can do stereotypically masculine or feminine things. For example men who do drag are generally dressing in a more classical feminine style. In the barbie movie, when the Kens took over they were pictured with a big hummer EV, not any of the other smaller cars we saw in the movie.
Macho is driving 120+ in 1000 or 1200cc Honda, BMW or Ducati, or other times a driving a cambered small car down the road at high speed as well. Or it could be going down the middle of O'Shaughnessy on a skateboard.
Fem is getting behind a 5000lb SUV. So it's no surprise women and families choose SUVs.
Individualism could be getting up early to bike all the way to Mt Tam, or getting up early to catch the surf. Collectivism might be taking the family out to a BBQ at the park, or going to the supermarket and doing the grocery shopping for the fam.
It's more profitable to sell us larger/bigger/scarier cars in the vehicle size/weight arms race.