This is easy. There were 20 of the ACR Convertibles built for Woodhouse Chrysler, Dodge, Jeep, Ram, Viper. They were done in white, yellow, red and black with various stripe or interior combos. This was a factory built car, with it's own code , listing ,etc., hence it is an extremely distinct model with just the 20 ever built. Have had some folks at FCA tell me it could be the most valuable Viper ever built as no other distinct model is likely to ever reach such low volume numbers.