Well first off good luck finding one. This is the last year for the SS. They stopped taking orders on them in May. So you'll have to find a dealer stocked one.
I love it. I, suprisingly so, love the compact size. It's great in traffic. Regardless of gear (5 speed stick) vs speed, if you give it the beans, the turbo kicks in and it takes off.
The interior size is just perfect really. Bigger than a compact car, smaller than the Equinox SUV, big enough for dogs, seats 4 adults resonably. Getting about 20-21 city (stickered at 22) as long as I'm not railing on it... otherwise it drops to about 18. Haven't done any real highway time with it. I think while I love the stick it probably negatively effects my mpg in the city. You tend to wrap the tach more...
I really liked the price. Sticker around $25k. I got like $4k in rebates, incentives, and retireree discoung as well as another $850 off in employee discount (x plan style). Have lots of family on wife's side that worked for GM.
I spoke about how some like it, some love it. Rider mentioned so do Prious lovers. That's totally different. Many people don't like the styling of the HHR. It has a retro, big fendered, 1930-1940s look to it. My MIL calls it my old school gangster car. She says when she sees it she remembers all the old gangster movies with the big fendered cars. I can see that. But it's the reliability and utility of the car that makes the owners love em. I don't know many other SUV style vechicles that can (normal hhr) do 30+ mpg.
Now on the mod front... since I did the LED's in the front the ECM put my blinkers in hyper flash... very annoying. The car has a ECM based, internal programmed flasher aka nothing I can just change out. So I ordered a resister from superbrightleds.com and installed that inline on each front blinker. Fixed, back off the homo hyper flash.
Had to install a smaller one on the dome light as well. Stray 6 volts on that circuit when they are "off" was keeping the LED dome lights just so slightly on, very dim. That fixed it and ate the stray volts.