"He's wanted for felonies in other states, is a drug dealer, and has unregistered weapons" well no one gives a hoot about that. His past criminal activities in this case appear to be irrelevant. Waht matters is what you can prove with respect to a contract. If you can show that you made payments (partial performance) and you ahd possession fo the car during that time, you should have a fairly strong case. Hard to justify paying $300/hr for an attoney over $1,000 transaction so focus on proving your case that you paid him over time for the car...good luck
This is not legal advice.
Keep track of all threats. You can seek a no-contact or anti-harrassment order and use the recordings and textes. But the real protection is limited. Nonetheless it does create a record. Do not hesistate to call the cops if you feel that you and yours are in danger.
Regarding the agreement:: Do you have a bill of sale? Who has title to the car? Do you have anything in writing about the terms of the sale? How did you pay? Cash or check? What evidence do you have of the payments? Who has the car? If you took possesion, did you insured the car? All of this can be evidence both direct and indirect of the agreement.
I am sorry but someone has to say it. What were you thinking? You entered into a long-term business transaction with someone “who is wanted for felonies in other states, is a drug dealer, and has unregistered weapons.” Did you really expect the transaction to go smoothly? I know it is too late to help you, but people, if you use common sense you can avoid many of your legal problems. Common sense would say do not do business with this guy.
This answer is not intended to be a substitute for personalized legal advice. I have presented only an overview of the legal issues. There are many nuances and some exceptions to general legal principles. Real problems are very fact based.. If you have a specific legal problem, you should consult an attorney. You can find more useful information on my law firm website resources page at www.marshallcomputer.com or you can contact me directly at firstname.lastname@example.org or (206) 524-0655.