The HHR looks sharp on the outside. Nice curves, cool retro looks, good paint. However, the inside looks like something out of a 1980's era car. Cheap foam plastic that scratches easily covers every inch of the cabin. The standard stereo puts the speakers on the floor, so it sounds muddy. Windshield is very small, so your field of view is a bit limited. The sunroof works well and the controls for it are well placed. There's also a handy in-dash storage space that holds an IPod, GPS, sunglasses, etc. There are three poorly places cup holders (which makes a trip in a car build for 4 interesting), back seat is very cramped.
Great gas mileage with 2.2L (30mpg+ on hwy!). Acceleration is nice despite smaller engine. Sun roof controls are well thought out. Dashboard gauges are easy to read.
The interior of this car is exactly why the US car industry has the image that it does. Embarrassingly cheap foam plastic, awkward window controls, cramped passenger space, a tiny windshield, and the fact I've had to have the car in for brake service 3 times in a year = poor car. Skip this turkey.