I've had a ratting, clunking noise in the front end since new, and so far put on Pedders springs and Moog end links. Did'nt cure the problem.
Dealers don't want to mess with it[long story] so I'm going to locate it, so help me.
Just orderd a Steadman Chassis ears, with six leads, to hook up to parts to locate the noise. The next few weeks or less I'll find out whats making the noise.
After I find out whats making the noise and fix it, I'm going to insulated everything inside and outside to make it quieter, and I mean everthing. "Moon"

 

Replaced my sway bar links today.... BAM no more clunk.

 

Sway bar end links are a common problem on the HHR, I have had both sides replaced before 50k. Next time I replace it will be with heim rod ends.

 

The one saving grace in all of this is that the front end is ridiculously easy to work on. The struts are easy to get at and I changed out both struts in an hour and I'm not that much of a mechanic. The hub was pretty easy too. If your any kind of a DIY guy change out the hub yourself. My son decided to take a freeway off ramp at about 100 plus and ran over the curb and took out the entire left suspension. The body shop said it would be 5 or $6,000. It cost me about $400. all new parts and a day to do the job. No frame damage the knuckle and drive shaft took the hit. But I put in new A arm, strut, control links, knuckle, drive shaft assembly and a stiffer sway bar which was the only thing that was a total pain to replace. Sorry I'm rambling.

 

My Noise started at 53K, on the drivers side. Had to change both front hubs ( after buying new tires to rule them out as a source of noise) its a pain without air tools but i did it in about 1-1/2 hours.
29mm socket for the hub nut needed and wire etc. to hold brake caliper unit from moving around while your trying to work.
If their rusted, try putting tire on and jiggling that around to loosen them up. Its one of those pain in the butt jobs but can be done by anyone with tools and saves you at least $500 by doing it yourself.