You deeds will tell you who it belongs too. If you have legal protection on your home policy you can get them to double check for you for free This site is useful as well http://www.boundarydisputes.org/
What a
I hope you get it back either through the courts or any other way I'm no legal person but how much does he want ? I thought if you paid for it and write on the receipt 'paid under duress' you can still fight for your money back and at least you would have your cars back