I have no idea what is going on, but just from what I have read I see three possibilities:
1. You have become personally attached to your cars which makes them very hard to sell.
2. You think they are worth more than others do, and you are trying to get top dollar.
3. You are a nut job.
Or maybe some combiniation of the 3? Personally I dont care. I think everybody has varying levels of the above, but maybe you have a little more 3 than most.
Good luck with whatever you decide to do.