A Treasure Hunt Car is a series car just like all the others. There are 12 cars per series year, one for each month of the year. Some of these Treasure Hunt cars have synthetic tires and look much different than the other series cars and make them more appealing to collector. These cars are on cards just like the other series cars and have series banners just like all the others. The one thing that make them really stand out is that they have either a dollar sign "$" on them or a picture of a treasure chest along with the series banner has always been he color green. You know, the same color as money
At first, these cars were very limited in production. In 1995, they were released with a production run of 10,000 for each car. This number was printed in the upper left-hand corner of the face of the card. With production numbers being that low, they were indeed a treasure to find and worth all the commotion they created.
In 1996, the production number was increased to 25,000 for each car, giving the collector a better chance of finding them. This number was also printed on the face of the card. This was the last year any production numbers were printed on the cards. It seems as time went on, the production numbers have increased and are not released to the public anymore. (From Hot Wheels Variations The Ultimate Guide : Written by Michael Zarnock)