Of course it's placebo, that's the point. What else could it be, some substance in the car? The point is that self-perception can influence brain chemistry and hormone production.
Maybe responsiveness; quick acceleration; "Road feel"; admiring looks from nubile women; defeated looks from men; knowing that you have more power available than you need; etc.
Be the porche. And it's free. I've noticed that porche drivers are mostly older people (presumably because, statistically, they can afford it).
To be picky: it also doesn't provide responsiveness (i.e. agility), but in isolation tends to muscle boundness. Easy to address with other exercise of course.
I could be the sound/vibration of the engine, the increased power/acceleration, the handling, the interior. I'm not sure all of these would classify as placebo in the traditional sense. But I'd agree it's mostly the pure placebo of knowing it's an expensive car.
Slam your foot down in the Camry, what happens? Slam your foot down in the Porsche and you're doing 150mph before you know it ... isn't the perceived danger also a large (non-placebo) factor?
