Given the option, my bet would be that people (those on the mid to low end of the economy anyway) would strip out just about every feature not essential to the car going down the road if it meant big savings. They'd ABSOLUTELY do if for 50% off. Safety features would be gone in an instant.
Cars don't come with airbags or even seat belts because consumers demand them, they do so because its the law. That's not to say safety features are a bad thing, just that their omnipresence isn't due to economic forces.
Maybe safety features are a weak force, but I know plenty of parents that buy vehicles based on safety features. Volvo is pretty famous for marketing their safety features and kid friendly features as a competitive differentiator.
Cars don't come with airbags or even seat belts because consumers demand them, they do so because its the law. That's not to say safety features are a bad thing, just that their omnipresence isn't due to economic forces.