I can't believe this. I just noticed this happening to my car too The difficulty is that when I notice the issue, it's at night (that's when my lights come on). At that point the dealers are closed.
This has only happened once in the past month but I'm getting the same symptoms.
My car is going in for some other work and I'll ask them to check it. Good to know the solution may be as easy as a bulb change.
I just got back from the dealer. I have a seal or gasket that needs replacing. When it rains, a little water is getting in causing my bulb to go out intermittantly. There is visable condensation in the housing too.
They said this is a problem they have experienced with the HID lights. The are fixing and drying everything up inside the housing. All covered under warrantee.
Not only did they replace the seal and dry things up, they replaced the bulb. He says that the bulb gets so hot even the oil from your fingers will reduce the life of the bulb. So with all the condensation, they believed the life of the bulb would have been shortened considerably. All under warrantee.
He suggests if I ever have to replace a bulb (even halogen), use a paper towel and don't touch the bulb with my fingers.