Amundsen+ my observations

I paid extra for the Amundsen+ system but I am a little underwhelmed by it. To my ears the sound is a little "rough" and distorted in the mids - as if there's a slight overload somewhere. It's not my iPod because it's the same on radio and CD too.

Has anyone upgraded their stereo systems with something else? Any recommendations? I'd still like to keep the cool features like Bluetooth, Rear Parking Visual Indicator, etc