There is a large group of people (maybe even the majority?) who, as soon as they get in a car, MUST immediately turn on the radio or some kind of extra noise source. Is this some kind of a Pavlovian reflex?

I'm always amazed by this, as my car is one of the few places where I have actual control over my environment (unlike on public transport, or at my workplace, or even in my home - neighbours can be noisy...). We are living in a sea of unwanted noise, bombarded by constant ads and "music", so it is nice to have a place of "quiet".