Never seen this convertible truck before !
Here is a link to all the '91 pictures with trucks that I have found over the years :
https://www.casimages.com/a/suZ43
There wasn't any white Dakota !
The conception of the 1994 pace car :
http://www.ebay.fr/itm/1994-Mustang-Cobra-Indy-Pace-car-original-design-concept-drawings-set-of-3-/252807476957?hash=item3adc7ff6dd:g:eacAAOSw9GhYk-7Q
Has anybody ever seen this one ?
1964 Indy 500 :
On sale on eBay here :
http://www.ebay.fr/itm/Original-Slide-Indianapolis-500-Pace-Car-Ford-Mustang-May-1964-/141930077611?hash=item210bb11dab:g:9AYAAOSwoudW52Sv