Despite having about seven fewer inches in length and two inches less in width, the 2005 Chrysler PT Cruiser is able to provide more overall interior room than the 2006 Chevrolet HHR. The PT offers an additional inch of rear legroom, about an inch more front and rear shoulder room, and an extra cubic foot of cargo room. For its part, the HHR has about a half-inch of extra front headroom.

Dimensions aside, the interiors of the Chevrolet HHR and Chrysler PT Cruiser offer similar designs. Among the likenesses are the shape of the dash (especially the passenger side dash panel), the large metallic shift knob, the independent fold-down center armrests, and the location of metallic door handles on similar two-tone door panels. Both models feature split-folding rear seats, though the seatbacks and cargo floor in the HHR are covered in hard plastic.