Some time ago I installed a DICE Silverline in my 2004 X5. I have had a relatively faint, but definitely audible, high pitched whine that varies with engine speed (Sounds like a dentist's drill). I installed the EAS noise filter - no luck.

I finally broke down & took it to a local car stereo specialist. They tried several things including a GFI and installing the noise filter closer to the unit - no luck.

They wonder if it could be the Dice unit itself. Before I ask for an exchange, does anyone have any thoughts?

Thanks.