There is only one way that I know of to make certain that your investment in a car will yield a positive return over it's purchase price.
1- buy it
2- keep it
3- do not sell it before you have owned it for 50 years minimum.
If it 's value goes up sooner, and most will, simply consider yourself brilliant and a financial genius.
Too late for me, but I do try to teach the younger ones.
That is all that you need to know.
Marty