One problem related to windshield wiper/washer has been reported for the 1999 Buick Park Avenue. The most recently reported issues are listed below.
1999 Park Avenue sensor for the rear windshield caused moisture to freeze on the wipers. The device caused moisture on the windshield to freeze onto the wipers. The end result was that the wipers would not clean off the windshield. The sensor caused the blades to move so quickly that they sped up the freezing process.