The original Grand Am was introduced in the fall of 1972 as a 1973 model. It was based on the GM A platform

GM A platform

The General Motors A platform was a mid-size car automobile platform. The A-bodies evolved from rear wheel drive compacts, to rear wheel drive mid-size cars, to front wheel drive mid-size cars over the course of 32 years. The switch in drive layout in 1982 spawned the G-body...

 (A-body) along with other cars such as the Pontiac LeMans

Pontiac LeMans

The Pontiac LeMans was a model name applied to compact and intermediate-sized automobiles offered by the Pontiac division of General Motors from 1962 to 1981. The LeMans was replaced by the downsized Pontiac Bonneville for the 1982 model year...

, Pontiac GTO

Pontiac GTO

The Pontiac GTO is an automobile built by Pontiac Division of General Motors in the United States from 1964 to 1974, and by GM subsidiary Holden in Australia from 2004 to 2006. It is considered an innovative, and now classic muscle car of the 1960s and 1970s...

, Chevrolet Chevelle

Chevrolet Chevelle

The Chevrolet Chevelle is a mid-sized automobile produced by the Chevrolet division of General Motors in three generations for the 1964 through 1977 model years. Part of the GM A-Body platform, the Chevelle was one of Chevrolet's most successful nameplates. Body styles include coupes, sedans,...

, Buick Century

Buick Century

Buick Century is the model name used by the Buick division of General Motors for a line of full-size performance vehicles from 1936 to 1942 and 1954 to 1958, and from 1973 to 2005 for a mid-size car....

, and the Oldsmobile Cutlass Supreme

Oldsmobile Cutlass Supreme

The Oldsmobile Cutlass Supreme was a mid-size car produced by General Motors for the American market. It was always at the top of the Cutlass range. It began as a trim package, developed its own roofline, and eventually was mechanically divorced from the later, smaller Cutlasses.The Cutlass Supreme...

. The GM A-body platform had major design revisions in 1973 that included the elimination of pillarless hardtops due to proposed federal rollover standards, but with frameless windows similar to that of a hardtop. No convertibles were produced due to those same federal rollover standards (that never were enacted).