Review on SYLVANIA 9004 SilverStar Ultra - High Performance Halogen Headlight Bulb - Brightest Downroad, Whiter Light (2 Bulbs) by Marc Zitnik

Sounds interesting so far, I've been using these bulbs for years. Both sides are always exchanged at the same time. Today a light came on completely, driver's side was very dark. I removed and replaced the bulb but will keep an eye on it. Never had this problem on my car so I suspect it could be either carbon on the spark plug or a possible defect. Will follow and see. However, I recommend keeping the packaging and proof of purchase. I've called on the warranty before when the lightbulb suddenly exploded. Sylvania handled that effectively. I will update my review if there are any issues. And please note that it is 1 TWIN PACK, not 1 bulb as the description says. (Revain says they're fixing that) but I hope this little info helps.