If the HID head lights are flickering or have failed, it may be caused by the window washer fluid leaking onto the HID modules. The washer fluid check valve for the head light washers develops the leak and drips onto the modules mounted under the head light assemblies.Google+
Car Problem Reports
Saab 9-5 Flickering or Failure of the HID Lamps
Saab 9-5 Problem
Average Mileage: 87,911 mi (35,000 mi - 149,576 mi)
Passenger sued headlight flickers regardless of low or high beam.
I was told by a mechanic that this is "typical" of Saabs and I should get used to it.
He added that it will be a lifetime of bulb changing and frequent stops by highway patrol for faulty headlights.
Visitor, 2006 Saab 9-5, 87,000 mi
Flickering started at 87K. Then it would flicker for a few minutes and then the pass side would go out, and a dash light would come on. It progressed over the next year (no, I didn't fix it and now the car has 105K on it) until both bulbs would alternate flickering and then go out. Time to fix it I guess. Inde Saab guy says it needs new bulbs - both sides at $190 each. Will report if problem not solved.
Visitor, 2004 Saab 9-5, 107,000 mi
Replaced both bulbs
Visitor, 2003 Saab 9-5, 92,500 mi
Flickering hid on drivers side
Visitor, 2002 Saab 9-5, 149,576 mi
Same HID problem with blown fuse on the pass-side
Visitor, 2003 Saab 9-5, 78,000 mi
Flickering of HID headlights!