I used to own a 2008 SS cobalt and before i sold it i kept the pioneer sub out of the back, is this something possible to wire into the HHR? i don't want over kill( i'm a family man and the wife and 1 1/2 old baby don't like subs) I can do a lot of work on cars, but i SUCK at anything related to electrical. i will Post picture soon to show you the full assembly as well as were i was interested in putting it if possible.

 

Here's couple of threads that might help, I'm thinking the Cobalt subwoofer is a 10" compared to the 8" in the HHR, but I'm not 100% sure.

https://www.chevyhhr.net/forums/show...ding+subwoofer

https://www.chevyhhr.net/forums/show...balt+subwoofer