I wonder if a live voting/reservation form with instant runoff (2nd, 3rd, 4th, etc. choices) would help matters.
If people could see how close something was to meeting a go/no-go threshold, they might be inclined to throw their hat into the ring to buy. Additionally, a site that constantly updates with the numbers could tally the alternate choices to say, OK, XYZ version won't get made, but we have enough 1st choices and 2nd choices of road ABC to get it done.