Normally you have the new car depreciation. Then as time goes by, miles rack up, you have a more gradual depreciation. Then the thing gets so old that as long as it remains in good condition, it pretty much hits bottom. If you are lucky, it becomes collectable and starts going back up. Then you throw in economy, competition and 'cool du joir' factor.
Differences in our cars. You can now, and probably 'forever' will be able to, pick up the phone and order a new one. That pretty much kills the collector thing unless your Cobra manufacturer goes belly up, and that might kill it to. Besides, unless there was something really different and desirable about your manufacturers cars, it isn't going to happen. There is the new car depreciation.
After that our cars hold value fairly well because in general, we are a fairly anal when it comes to taking care of them and don't drive drive them as much as most cars. We tend to overmaintain and rebuild/replace before it is really needed.
While my car is just a couple of years from legitimally being able to get collectors plates, I sure don't expect its value to go up.
Buying cars as an investment is a very tricky business. In general, don't do it. You certainly should not look at any modern Cobra as a sound financial investment, not even the ones from SAI.
Do I expect SPF (and others) to loose a few sales to SAI because of the new CAV SAI, sure. Will it hurt SPF, doubtful. Everyone seems to be doing fine with SAI in the game and it is a damn cool thing to be able to pick up the phone and order a Shelby Cobra.
I bought the car because of what it represents to me and as a hobby. I get a real thrill out of making it a better car. I know, with out question, that I can make the car a better car than it is today, that is part of what I like about it. It is already better than it was. My 'to do' list will probably last until retirement. When I do retire I will probably pull the whole thing apart and do it all over again. That is its value to me.
Seems to me, in general, those who turn the cars rapidly or frequently are still searching for what makes them happy. Not a damn thing wrong with that. Us Unique owners just seem to find that peace sooner than others

(for you Al)
Rick