Sounds to me like this is the very rude and dangerous-to-other-drivers high-intensity discharge system. My first comment to the dealer would have been "what kind of cars are you building if "everything needs TO BE changed out". It only takes one part to cause a problem. To say they need to replace an entire system suggests they don't know how to diagnose the cause of the problem. Any idiot can fix a problem if they replace everything. Even I can do that.
If you have the normal halogen light bulbs, besides the vibration that exovcds suggested, which is a very good possibility, also suspect the bulbs were installed previously by an inexperienced mechanic who grabbed them with his bare hands. Fingerprint oil will burn through the glass very quickly. High-quality bulbs come with foam packing material around them to allow you to handle them. Less-expensive bulbs at least come with a piece of paper telling you to not touch the glass.
Another potential cause is water buildup inside the housing from a leaking seam. The water splashes up onto the hot bulb and cracks the glass. Someone would have seen the "fish aquarium" minus the fish by now. This is a legitimate reason to replace the housing and bulb, but I wouldn't be so condescending as to call that "everything".
Saturday, December 29th, 2012 AT 12:02 PM