Why do some people play loud music in their cars and drive around with the windows open?

I don't understand why people do this. When I see (and hear) a man (it is usually, but not always, a man) driving around with the windows down, inflicting his (usually) ghastly music on everyone, it leads me to make a low estimate of his intelligence, attitude, and *ahem* size. Everyone I have asked feels the same. So why do people do it? Are they of such limited intelligence that they think other people *want* to listen to their noise? Or do they just not care?