The General Motors H platform or H-body is an automobile platform designation used for the 1971–1980 model year rear wheel drive line of subcompact cars. The fourth character in the Vehicle Identification Number (VIN) for an H-body car is "H". The Vega and the Astre were discontinued at the end of the 1977 model year, but the Monza, Sunbird, Skyhawk, and Starfire continued through 1980. The GM J platform replaced the GM H platform in 1981. The H platform designation was later used for the unrelated front-wheel drive GM full-size cars in the 1980s.