illegal registration of sold vehicle

[moniac]

I bought a motor home last year when I was living with a man.
I was the one who paid for all of the financial part of it, and he, being a
great fixer upper type, did all of the mechanical stuff.
We broke up and because of the age of the rv I sold it to him, at a loss,
but I knew I would not be able to maintain it on my own, and he loved it.
I was the one who also paid for the registration and insurance for it.....
The problem is here:
He did not want to pay for insurance, so he registered it in both of our
names again.
I sent AAA a release of liability when I sold it to him, but for some reason
when the registration still came to both of us, and he took advantage of
this situation.
Do I have rights to this rv still?
What legal actions could and should I take?
I really wouldnt mind having possession of the rv again, especially since he
took advantage of my kindness.