Every time you hear of one being wrecked increases the potential value of your car. Just like the story of the guy who has the only two stamps of their kind in the world, he is told by an appraiser that they are worth a million dollars each, upon hearing that he tears one up and asks how much is this one worth?
These cars are practically at rock bottom now depending only on condition to get a better price. How much is a twelve year old mustang worth say? Not much. Any car that runs and will pass the various road worthiness tests is worth maybe two thousand bucks or so, it might be a Crossfire, but it is not an ideal day to day beater for winter so maybe it will get to an even lower price level.
Only the fact that the car is a bit different warrants the price they do get, some of the mods being done to some of these cars is condemning those particular cars to even lower values. In the end the car is only worth what someone will pay for it, that is the way it was and still is.