Sure, I am asking that question, I'm also trying to answer it. I think seat belts do modulate the perception of safety and do make car travel feel more dangerous. To what extent I don't know, but consider how their affects are balanced by other sensory affects of car travel - comfortable seats, the sense of being surrounded by a metal cage, less exposure to the outside elements (sun, wind, sound), no build up of adrenaline or other hormones from physical exertion... there could be more. [Anecdote: the safest car I've even been in and driven was my later grandfather's rolls royce. Drove like being on a cushion of air and you could hardly hear the very powerful engine. Possibly partly why he drove like a careless maniac.]

I imagine that cars over the decades have not just been designed to be safer, but have been designed to feel safer, because that is appealing. This design concept would work for bicycles too - uprights and cycle-share bikes for example. I'm certain for sure that helmets to do not make cycling look safer nor feel safer for most people (there must be exceptions - its been said here before that helmets increase risk taking). I think its kind off relevant to the other thread because when bike shops push the sale of helmets they may be losing bike sales or repair jobs as a result, as was suggested. Anyway that threads closed so sure we can continue here, though its been discussed here before I reckon - probably about a 100 times!