cars are irrational because theyre inefficient compared to public transport since as we know its usually 1 person to a car.Whether a decision is rational or not depends on the individual circumstances. A rational car purchase for one could be irrational for another.
Yes.
advertisements undermine market principles by promoting irrational decisions for example buy a mercedez SUV or hummer SUV or any SUV when really all you need is a sedan and btw you should have public transport.