I was quoted $800 to repair my control arms in my 2011 HHR LT. Is this correct? Seems very high.........

 

The flat rate is 1.8 hours + about $202 each for GM parts. (based on a 2015 database) Gmpartsdirect quotes $236 retail/$146 internet each.
If you can find a independent shop that will use your parts they are much cheaper on Ebay. Not a difficult job for someone with a few tools.

 

Just changing the rear bushings and ball joints is fairly easy and less expensive, if you have a press tool.

 

Is it recommended to change both control arms at the same time?

 

Yes

 

I paid $150 for my lower control arms from Amazon. There are actually three different types of suspensions FE5, FE3 and FE1. The FE5 and FE3 suspensions use an aluminum lower control arm whereas the FE1 uses a steel lower control arm.
I had my control arms replaced and installed with a wheel alignment for about $500. That also included putting Energy Suspension sway bar bushings on.

 

All HHR lower control arms are aluminum, none where factory equipped with stamped steel arms , those are from 4 wheel stud Cobalts and Pontiac G5’s plus other assorted Saturn’s and Saab’s

 

Sorry to say you are WRONG about FE1 being steel. All HHR came from the factory with aluminum. FE1 and FE3 are interchangeable.
The major difference in the FE5 part is the ball joint. Unfortunately, most of the parts books are unaware of this fact, including the GM book.

Many are confused because they ASSuMe that all Cobalt parts interchange with HHR.