My stepfather cosigned for my car, he is now deceased. I've always made the payments on time. What happens when the car is paid and I want to get the title in my name only? And if the finance company finds out he's deceased, what will they do?

Co-signer is not co-owner unless you put them on the title.

If they are also co-owner how are they listed, it may be as easy as showing the death certificate, or if it is listed one either one can sell the car, just your name.

And he was just a co signer, his estate would still have liablity on the co sign I don't know of anything they can do,

But it depends on the written terms in your contract