The stock radio in my '91 E30 318i has a problem with the volume control. It's the kind of volume control with little step detents rather than smooth movement. When I first turn it on, the volume comes on at some set level that doesn't change as I turn the control. I have to turn it almost all the way off and then up and down a few times to get it to change volume smoothly rather than jumping from medium to off and back. Any easy way to fix this? The fix would probably start with me buying that funny tool to pull the radio out, right? Thx, Ron