The HHR gets great mileage on long trips about 33mpg, however mine is a manual transmission. The interior needs more cup holders there are only three right down the center console. So with that said there are two in the front and only one in the back for rear passengers. This is a very fun car to drive and is very soild like a truck but rides like a car.
I like the folding rear seats and the amount of storage behind the rear seats, most larger suv's don't even come close to the storage or gas mileage of this vehicle. Also I average about 25mpg around town with this car.
Chevrolet needs to figure out the wiring problems with this vehicles ignition switch, I have had 3 put in and I just reached 17,600 miles. The cloth seat material has also worn out and the driver's seat had to be replaced after I vacuumed it the material simply came apart, and it was not a seam.