Do you hear?
 

----the rear supension when you go over bumps?

Just alittle.. I have noticed that a few weeks ago. May have to take a trip to the dealer.

Mine makes noise in the front. My 06 did too. The 08 didn't make noise at first when I got it (5K miles) but now at near 7K it has started squeaking when cold just like the old one.

Every once in awhile i get a Noise coming from the Rear. Usually when its Cold out.

yes. when cold. it sounds like i broke something

rear noise
 

yep I hear it too and it happens more when it is cold-its a k-thunk kind of noise-let us know if you figure it out.
Lake
082lt

Same here on both of our 2006 HHRs. When winter arrives and temperatures drop below 32 degrees, the rear thump noise is noticeable on bumpy roads. Goes away as soon as it warms up outside.

I hear a clink sound when I hit bumps.
Sounds like there is some steel in the cargo area that I'm hauling.
A higher pitched clink sound.

Ya it happens to my 06 HHR. It only happens when the engine is cold though.

I thought this might be gasoline sloshing in the tank? My HHR is pretty darn quiet still, 22,000 miles.