i HATE the dealerships.
I have a 2002 XC and have noticed that the reception was starting to get a little crackely, i managed to fix theis temporarily by removing the hu and fitting in a new deck and tv. this worked for a little while and i am now starting to get a few crackles again, this leads me to think its something to do with the ariel or the cable from ariel to hu.
good luck with the dealership, i try to avoid them as much as possible.