05 S60 headlights are absolutely terrible (my 01 with glass lenses shines down the road at least a half mile). I have tried a meguiers restoration kit which made the lense look better for a few months but did not improve the visibility at night. I have HID bulbs and just found out that there is also a ballast for the bulbs. Do HID bulbs go bad slowly or all at once? I don't want to waste $200 on new bulbs if my ballast might be bad. Thanks for your help.