I have put about 100K miles in 5 years on my 2007 and noticed last year that while driving on the highway one of the headlight bulbs started to flicker and then went out. It came back on later and I think it has been working pretty reliably. I really don't check too often. Today I was driving and making a turn in a parking lot. The headlight was on a building and I could clearly see it flickering. Is a flickering headlight or one that goes out but later works a sign of something other than a bulb failure? I don't want to replace an expensive bulb that still has life left.
If you end up needing bulbs, I've purchased from this business previously and had very good luck with the bulbs. Buy them in a set for about $70. Replace them both at the same time. The 4300 bulbs are direct factory replacement. D4R Bulb - Factory HID Xenon Series | Onyx Performance Lights