You are the only one with the correct answer. I finally figured it out by observation that when the automatic headlights are on, the small LED white light is on to let you know in not so obvious conditions such as a cloudy and rainy day. To confirm, look up at night and you will see it on...and my 2008 has a rear dome light...

 

Thank you for solving the mystery. My 2009 HHR got backed into by a person leaving a party outback. So anyway, it was getting repaired and the Chevy dealer gave me a loaner car. An orange 2008 HHR. Mine is black, not a fan of orange cars, and this one was pretty beat. But I saw the little led light, couldn't figure out what the heck it was for. Thanks for solving the mystery. Thank goodness I got my HHR back last night, it was only 3 days but I missed it!

 

My old 2008 did not need a rear dome light because.... the map lights on the mirror served the front seat and the map lights on the forward dome served the back seat. In other words, there is no dome for the FRONT seats.

My 2011 has no map lights on the mirror, but has 3 dome lights (one for cargo).

 

"My old 2008 did not need a rear dome light because.... the map lights on the mirror served the front seat and the map lights on the forward dome served the back seat. In other words, there is no dome for the FRONT seats."


Don- That is when many of us did the "Dome light Spin" mod to have a dome light in front..

 

I kinda wish they continued with the map light. My buddy has one in his '08 LS, and its useful for other things then lighting up the buttons.

My '10 LS just seems really.... dark at night. Then again, I have black trim...

 

After 18 months, I still look up there to see if it is lit. traded the 08 for an 11.