Zkw brand xenon headlights - the back of the projector bowl is made of plastic (vs. Metal in the al/Bosch brand, also used by BMW), which over time burns from the heat put out by the headlights. The burn turns the plastic from white to brown/orange, which severely reduces light output, making night driving dangerous. I don't feel comfortable driving at night unless my hi-beams are on, which is hard to pull off unless I'm the only car on the road. This issue is most prevalent in 2002-2005 3 series sedans, and the issue is well documented in the BMW community.

- Kenmore, WA, USA

Zkw reflectors on hid headlight assembly degrade, greatly reducing the headlight efficiency at night. The plastic of which the reflector bowls are made degrades from headlight heat, and the reflective coating burns.

- Cambridge, MA, USA

In 2002-2005 BMW 330I sedans with the xenon headlight feature, BMW opted to use zkw brand headlight assemblies instead of al/Bosch brand assemblies. The zkw brand assemblies have plastic projector reflector bowls whereas the al/Bosch assembies have metal projector reflector bowls. As a result of constant heat and concentration of the xenon bulb on the plastic projector bowl, the reflective surface begins to deteriorate. Soon enough (after a few years of use) the bowls receive brown/blackish burn marks from the concentration of light. The burn marks no longer reflect the xenon light and cause the output from the xenon zkw headlight assembly to be fainter than original state. Numerous individuals on the BMW car forums have experienced similar problems and have made note that this is the cause of their failure. Note: Some 2002-2005 330I sedans did come with al/Bosch brand headlight assemblies.

- San Francisco, CA, USA

2005 BMW 320I. Tail light indicator warning came on. Turns out the wire was melted around the metal where the wire plugs into tail light!! very expensive to fix!

- Truro, 00, USA