Interesting, I agree that it could possibly do with a weighted algorithm that keeps your cars, ones you have commonly driven or valuable ones effectively around for longer or makes it effectively so. I mainly asked as we kind of went off topic and onto GTA in a thread I made the other day ( http://gbatemp.net/threads/analyse-a-popular-game-you-do-not-like.347155/ ) and more opinions are good.
Ah yes, I can't say I disagree with those points.