One problem related to headlight concealment device has been reported for the 2008 Toyota Prius. The most recently reported issues are listed below.
The contact owns a 2008 Toyota Prius. While driving at approximately 55 mph, the headlights failed without warning. The vehicle was taken to a dealer where it was diagnosed that the concealment devices accumulated moisture, which contributed to the failure. The lights were replaced but the failure recurred. The manufacturer had not been notified of the failure. The failure mileage was 150,000.