Unproduced: Rapid Fire Tank
Pictured above is a resin and fiberboard prototype for a vehicle that was named G.I.Joe Rapid Fire Tank. The "Rapid Fire" seems to have been intended to be a repaint of the 1994 Blockbuster Tank.
Or, the Rapid Fire was eventually renamed the Blockbuster. If that's the case, then the image above is probably a prototype of the Blockbuster and the name must have been changed at some point from "Rapid Fire" to "Blockbuster".
From the collection of: Steve Campbell