Took delivery of a Cocoa CXL, Ent package #4. After a few days, I noticed a high pitched noise coming from the passenger side tweeter. It only occurred while listening to XM and not the radio, CD or DVD. Took it into the dealer and they said they needed to replace the Nav/Radio head unit. Part arrived in 4 days and much to my surprise, it was installed in 1 hour. Sound is gone and speakers work perfectlly. Just wanted to share this and find out if anyone else has had this problem.