Should I Choose Car Perfume According to the Most Fragrance-Sensitive Regular Passenger Rather Than My Own Preferred Intensity?

Yes. I would put it more strongly than that: your own preferred intensity is not a usable input, and the reason has nothing to do with whose feelings matter. Here is the doctrine, stated plainly. The level of fragrance in a shared vehicle is set for the most fragrance-sensitive regular passenger. Not negotiated, not averaged, not set by the person who paid for it. Set for that one person, recorded, and then left alone. And here is the justification, which is physical. Two independent facts stack up against the driving seat. The first is position. Whatever is releasing fragrance in a car sits within arm's reach of the driver - a bottle in the console, a unit on the mirror, a device in the cup-holder - so the driver experiences the most concentrated version of it that exists in the vehicle. The second is adaptation. Olfactory receptors are built to report change rather than state; a constant stimulus stops being reported within minutes, which is why you cannot smell your own home when you walk into it and can smell somebody else's immediately. Put those two facts together and you have a person sitting in the strongest position in the car, receiving almost no signal, and holding the thing that decides how much more goes in. That is the worst possible arrangement of instrument and control, and it is the arrangement every owner is in. What follows from it is uncomfortable but simple. When you decide from the driving seat that the fragrance has faded and needs topping up, you are reporting something true about your receptors and nothing at all about the cabin. When a passenger gets in and says it is strong, they are reporting something true about the cabin. Those two statements are not in conflict and the passenger's is the one that is about the car. So who exactly is the most fragrance-sensitive regular passenger? This is the part worth being precise about, because the rule is sometimes read as setting the level for the most sensitive person who has ever been in the vehicle, and that is not what it says. Regular means in the car often enough that a wrong level affects them repeatedly - weekly is the useful threshold. Count those people. Among them, identify the one who most consistently notices, and set the level so that person does not. Occasional passengers are not a purchasing problem; they are managed on the day by ventilating the cabin and driving the first ten minutes with the windows down. Three practical consequences. First, record the setting - two presses aimed low and rearward, speed one with the two-hour timer, whatever it turns out to be - because you will not be able to re-derive it from the driving seat in a fortnight. Second, make that level the resting position rather than the reduced position, because raising a level is a private act and lowering one requires somebody to object out loud, which they will not do. Third, start from a restrained composition: a passenger-set level begins from a much better place with a quiet scent than with a dense one turned down, and no setting converts one into the other. And the condition under which this rule has no content: if you genuinely have no regular passengers, there is no most sensitive one, and you should set the car exactly as you like it. The doctrine is about shared cabins. It says nothing about yours.