I'm glad someone else hears the adjustment in volume besides me. I can hear it plainly - but it is very subtle. Passengers claim they can not hear
any difference.

One option that I like in my other car is that the volume will automatically readjust when you shut off the car. That means when you were rockin' out on a good song at full volume before you turned the car off, it won't come back on that loud and scare the crap out of you when you start the car.