I had bulb issues, and found that there were issues with the seal where the bulb seats, make sure there is no dirt there or any part of the old seal, I cleaned up the seal seat and ensured I had the bulb seated in the new seal and my bulbs have lasted for 2 years so far

 

On the HHR headlight it is very easy to miss removing the old gasket, then trying to put the new bulb in with it's included new gasket. If you don't realize what has happened you give up assuming that that's the way it is. WRONG! a. the light will not be centered properly. b. the bulb can vibrate causing the hot filament to break. c. leaving a plave for water to infiltrate.

You have to be sure that the bulb is securely locked into position. That is not easy to do, since you are working by feel with some pain, but vital.