[Dangerous Doug]

I think anyone pursuing a "car held hostage" better get beyond the "hostage" thinking and realize that the auto has true sentimental value to the rightful owner---the person you're trying to convince to sell it. Unless you can convince him/her that you're not just another greedy SOB and that you actually respect him/her as a person and can wait until they are ready to let go, you're not going anywhere toward a purchase.

Respect. Let them know you are interested and give him your number. Drop by or call and talk about cars. Listen to some stories about the car, and what made it special to the owner. Be a friend. And maybe...

DD