It sounds like the cars might have slightly more than broken even on cost for you which sounds like a terrible investment option when you've got everything from real estate to mutual funds that will generally outperform cars - and, much like stock picking, most of the models you purchased didn't significantly appreciate - just one ended up gaining in value.
I suppose I was misinformed in that I thought that cars of all value ranges were pretty disastrous assets to hold - but it sounds like holding on to them for value appreciation still isn't a particularly good tactic.