I have a fairly powerful aftermarket system in my car...about 300W total.
And I'm an audiophile...no doubt.
But when I'm on the road, I keep it turned down.
I feel that imposing one's taste in music on others is an invasion of their space.
And IMO, it's not wise to advertise that you've got a powerful (read: expensive) system.
Someone will hear it who wants it for themselves.
