Maybe, maybe not. Cars to me are not investments. They're depreciating assets that are either transportation or recreation or some combination of both. I wouldn't pay the large premium for the Mustang on the hope that it would overcome the price disadvantage by someday becoming collectible.
This logic never made sense to me. Just because something is a depreciating asset does not mean it is not an investment. It's not a GOOD investment obviously, but you can still mitigate your loss (improve your return) by taking good care of it. It's up to the owner whether that improvement in return is worth the care.
It's really no different than a house. Sure your home is likely to appreciate based purely on the value of land. But the interior of the home (kitchen, bathes, etc) will naturally depreciate over time as they go further out of style and suffer wear and tear. Taking good care of those depreciating portions will mitigate your loss on them if you were to sell without renovating.
Everything one buys is an investment. A lot of them will have virtually no return in the end, but a car is rarely one of them.