included black or white stripes that ran the length of the car and around the back, a Rally Nova sticker on the driver's side of the hood, 6-slot Rally wheels, multi-leaf rear springs, and a "sport" body colored driver's side mirror that was adjustable from the interior. The well-hyped Vega stole sales from the Nova this year, but the compact soon would enjoy a resurgence of popularity that would last deep into the 1970s. A mid-year production change was the front door hinges spot welded to the A-pillar and the door shell, a design shared with the Vega and later implemented by GM's subsequent light-duty trucks and vans which later was used with the S10, Astro van, and full-size trucks commencing with the GMT400 a decade later. The six-cylinder engine was now the standard Nova engine with the demise of the four-cylinder and six-cylinder engines. The and V8s were carried over from 1970 and all engines featured lowered compression ratios to enable the use of unleaded gasoline as a result of a GM corporate mandate that took effect with the 1971 model year. After 1971, other GM divisions began rebadging the Nova as their new entry-level vehicle, such as the Pontiac Ventura II (once a trim option for full-size Pontiacs to 1970), Oldsmobile Omega and the Buick Apollo. This was considered to build brand loyalty with respective GM divisions although the company later fused their badge engineering with platform sharing to cut expenditures. The initials of the four model names spelled out the acronym NOVA (Nova, Omega, Ventura, Apollo). The 1973 introduction of the Omega and Apollo coincided with the subsequent oil crisis where sales of the X and H platform increased. The 1972 Nova received only minor trim changes. The Rally package option with special suspension returned and was a rather popular choice, with 33,319 sold. SuperSport equipment went on 12,309 coupes. Nova production moved to Norwood, Ohio, where it would be assembled alongside the Camaro. At mid-year, a sunroof option called the Sky Roof became available on two-door models. Also, the optional Strato bucket seats available on coupes switched from the previous low-back design with adjustable headrests to the high back units with built-in headrests introduced the previous year on Camaros and Vegas. Despite the lack of change, Nova had its best sales season in years, with the production of the 1972 models reaching 349,733. Of these, 139,769