your right Barry - in checking I do find that also.

in a Wikipedia search 'Plymouth Road Runner' - this came up

'In 1971, the coupe bodywork was completely changed to a more rounded "fuselage" design in keeping with then-current Chrysler styling trends, including a steeply raked windshield, hidden cowl, and deeply inset grille and headlights. In a departure from previous thinking, the B-Body two-door bodies shared little if any sheet metal, glass, or trim with the four-door bodies. The convertible was canceled. The interiors could be ordered with 6-way power leather seats, thick deep-pile carpeting, and additional sound-proofing was installed. A/C, and power steering could be had, except on the Hemi. 1971 was a high-water year for ride and handling for the Road Runner.'

not sure how true that is?