Is this a new phenomenon?

I only really noticed it this year during the hot weather (correction - fair weather days) when a lot of people (all age groups) drive cabrios or with the windows down (even with the windows closed you can still hear the base).

I'm not quite sure what the driver's/passenger's message is supposed to be - is it 'this is my favourite song' or 'this is what you should be listening to'.

Perhaps not so noticable in cities, but in the sticks you can hear them from a long way away.