I sell a lot to Mr.X owner finance. Mr.X make payments for a while and then stops making payments. I decide to foreclose on the property but then I find out that Ford Motor Company has put a lien on the lot because Mr.X didn't pay them either. If I foreclose on this lot, will I be responsible for the lien filed on the lot while it was in the possession of Mr.X?

Did you actually owner finance or did you do a contract for deed. In case of a contract for deed you never put title ( deed) in their name, so the other company can not legally put a lien on property.

If you did a pure owner finance, you put a first mortgage on the home, so any other lien is a second mortgage. So when you foreclose the property is sold as it is suppose to be in a foreclosure at the court house steps and any money is first paid to the first lien holder, if there is any over that amount it goes to the second.

Many states allow you as 1st lien holder to bid the amount of your own mortgage thus if there is no higher bids, the property will go to you and the second lien holder is merely out.
But the laws of your specific state, and the actual mortgage paper work ( what is allowed in the lien you established when you sold the property)

OK, thanks =o)