I have had the same issue with the radio as Aero Blue. Happened a couple times during the first month I had the car. Dealer checked it out, and of course the could not duplicate it. It has happened again a couple times since. (I bought my roadster 4-30-05.) Each time restarting the car solved the issue.

Best thing to do, if it is possible, is to drive to the dealership when the radio is malfunctioning. Thing is, usually that isn't possible.

Hopefully my car is coming out of winter storage 4-1 (weather permitting). I plan to take it right in (again, if possible), especially since I now know the cost to replace is $2,500.