Ballys issued a set of four ncv cars which were available as part of a jackpot on certain machines. The set came in a velvet box. The machines were not the usual strike machines. In 1998, I played them in 25 cent and 50 cent denominations and I believe they were also available in $1.
They are shown in Archie's books, probably in the silver strike section. The value he listed was $150 and will probably be higher in the new edition.