I have a customer who has had an AVIC-N2, CD Changer, and XM in his truck for about 2 years - no issues.
I just put in a new N4, used all the same cables, just swapped out the brain and monitor and now any time you press a button, there is a staticky buzz in the speakers. Not all the time, ONLY when you press a button. WTF???
Can't be a wiring or grounding issue since the N2 worked just fine.
Vehicle is a 2004 Dodge Ram w/Infinity sound.
Any ideas??