The F40 is in the game (from GT5: Prologue).F40, F50 & Testa Rossa (or 512TR as known in later years) are glaring omissions from the Ferrari line up as all worthy cars from the respective periods that they came from. With the F40 being universally recognised by a number of experts as the greatest of all time. The other half, the McLaren F1. Either way both cars are insane.
Perhaps I misunderstood your post...