In 1991 Carroll Shelby drove the prototype Viper as a pace car at the Indy 500. Chrysler was going to use a Mitsubishis until the UAW stepped in with LOUD complaints.
Shelby: "So I drove it for 30 days, taking everyone for rides around Indianapolis (in the prototype Viper)" (from Carroll Shelby by Rinsey Mills, page 509.) A search of images in google has more than one photo of Shelby and the Viper at Indy.
Usually the pace car company has to provide Indy with ?? amount of cars to be used during the month by Indy people. I really don't know what Chrysler did in 1991 as there was only one (?) prototype in existence at the time.
Shelby had started to build a prototype Viper at about 3000 lbs in California, but according to him, he never finished it. It was powered by a Chrysler V8 (iron block 360?). He wanted to build an aluminum block V8, twin turbo, 3000lb Viper. Before he could do much, his heart problems kicked up and he dropped out of active work with Chrysler. Chrysler pulled the program back to Detroit and the rest is history, as they say.