The ultimate Cavalier Mark I is the design concept by Wayne Cherry called Silver Aero. “Silver Aero” was a one-off Prototype build in 1980 based on the Cavalier MK1 Sportshatch. The car was displayed at the International Car Show at the NEC in October 1980. The plan was to offer existing Sportshatch owners and buyers to upgrade their car to the Silver Aero spec. The car has a 2.4 litre turbocharged engine which produces . Orders were taken but not enough to warrant production, and the car remains a one-off.