(wooden framework with a special epoxy plaster) was shipped to the DMC office in Michigan on July 31, 1975. This mock-up served as the template for the prototype. The original full-size epo-wood DeLorean styling model was modified in the first quarter 1979 to reflect the refreshed design used in production. The mock-up was donated to the Ulster Folk and Transport Museum, in Cultra, County Down (Northern Ireland), where it is now on display. Prototypes and pilot cars Only one of two DeLorean prototypes still exists. Prototype 1 was sold at the bankruptcy auction in 1984 for $37,000. The car remained in a private collection until 2005 when it was sold, received a complete restoration and is now on display at the AACA Museum in Hershey, Pennsylvania. Prototype 2 was sent to Lotus Cars for development and evaluation in 1978. It was reported to have been destroyed in the 1990s. An estimated 28 pilot cars were built. The pilot cars are best identified by the subtly different interiors and sliding side windows. These cars, used for evaluation and regulatory testing of the DeLorean were previously thought to have been destroyed. However, a few of the pilot cars have survived and are owned by private parties. Visioneering car With the 1980 NADA meeting approaching, DMC planned to show a final production version of the DeLorean; however, there were no production cars ready at the time or even any production stainless steel panels. Earlier, in summer 1979, the revised Giugiaro styling mock-up was shipped to Visioneering, a Detroit based company, to create data needed to make the stamping dies for the stainless panels. This project expanded to create dies used to create a "production" car for the NADA show. Using a prototype chassis supplied by Lotus in late 1979, Visioneering completed the assembly of this car at a cost of $750,000. The car was presented at the 1980 NADA show and was later used for engineering development and technical training as well as press photos. The Visioneering car eventually was sold at the bankruptcy auction in late 1984 for $21,000. The car is in a private collection. Legend turbo cars It was determined that the DeLorean needed additional power when automotive magazine road tests showed times for the DeLorean between 9.5 and 10.5 seconds, while its rivals were in the 7.5–8.5 seconds range. There had been interest in turbocharging the DeLorean early on,