donbrew

Odd that the manufacturer would hate their own vehicle. Usually it is the brakes that limit towing; The SS has better brakes than LS/LT.

From page 5-32 of the 2010 HHR Owner Manual:

That sounds a lot more like a disclaimer than a prohibition.

Oldblue

Because you have to cut the rear bumper cover ? To fit the hitch

Casa Del Gatos

Nice AA5.
Curious what kind of performance effects and fuel efficiency you experienced.
Especially on a nice long trip where you can get numbers.

Blue_SS

This.

Mine was professionally done. Welded after receiver pushed through fascia (minimal square hole). It was like that when I bought it. I used it for a bike rack a couple times, but wouldn't tow much with an SS, either.

OP, those wheels are sweet on a black one. Not sure I would have liked them on other colors, but that's a clean look.

Oldblue