General Motors decided to expand its compact line in the early 1970s and the Omega was Oldsmobile's version based on the successful Chevrolet Nova platform. The Oldsmobile Omega parts were a bit more upscale then the Nova though. The first two years were basically Novas with restyled front ends and then the car was redesigned in 1975 with different styling but still on the same frame. The Omega switched to General Motor's front-drive X-body platform in 1980. One to watch for is the two-tone, plastic-fendered SportOmega. This model lasted only until 1985 when all the X-body cars were discontinued. The Omega name was ultimately retired and replaced by the Calais.