I just had the tires replaced, I am very happy that the ones I had from the purchase date lasted more than 76,000 miles, but I have two bent rims, and I have already had one rim fixed because of the same problem. Does the "low profile" of the car make it easier to bend rims? My alignment is fine, I don't understand how the rims could be bent but my alignment is not altered. I don't know really anything about cars, but this seems odd to me.
Great gas mileage.
Your HHR LT has custom aluminum rims. Aluminum rims bend more than the old fashioned steel rims because they're not as strong. I always make sure that the car I buy has steel rims. Aluminum rims get scuffs and nicks much easier than steel ones too and they're more difficult to repair. If this is the only thing that's happened to your HHR, you've got a great car! Just go to the junkyard and buy some used steel rims from a Cobalt or HHR. Make sure they're the same size as your old ones.
Are they "out of round" or simply bent from hitting curbs etc?
Some alloy wheels do go out of round from even hitting potholes. Of course they will dent if you bounce off a curb now and then, and the rims tend to take the hit when you have low profile tyres.
The lower ride hide ("profile" as you stated it) should not cause your rims to bend out of shape. I've owned plenty of smaller, lower vehicles in my life, and I've never had any issues with the rims.
If you are hitting very large bumps at high speed, that could bend your rim, however, it also would throw off your alignment as well. Are you sure it is aligned correctly? Not trying to be insulting or anything, but you said you don't know much about cars. When your driving on a straight road, look at your steering wheel, it is perfectly straight? If it isn't, then your alignment is off.
Bent rims could also be caused by severely underinflated tires, or driving on a flat tire.