Roger - I had a service approximately four months ago and the print-out shows the cabin filter was replaced. To make sure, I checked it myself the other night and it appears new and clean. A whistling sound is still heard off and on when the a/c is on or when just the fan is blowing. The fan speed problem is also an occasional deal. I am scheduled to take it in to my indie on Wednesday. He stated the problem sounded like the cabin filter and/or the regulator and, if so, it could cost $300 - $400. I am not enough of a DYI-er to tackle something of that nature - so guess I'll get the checkbook ready!