GM Prototype 1992 Oldsmobile Achieva Convertible. The car is a prototype convertible built by GM in 1992. This model was the first year for the Acheiva and I have all the documentation showing GM Prototype history. The car was purchased from GM after they went into Bankruptcy and were forced to sell all of their prototype and concept cars at auction to raise money. Most prototypes don't have a Vin# because they are custome built cars, this one does because it started its life as a coupe and was customized by GM into the Achieva convertible. This is a one of a kind car and the only one ever created by GM. It is now a 25 year old anitque car that is brand new and only has 320 miles on it. The car is currently register in Rhode Island. Once again, this is a prtotype from GM and was customized. that's what it means to own a Prototype. Thanks for looking, asking price $12,500 or best offer.