Contract for sale of car
The contract states I agree to buy my sisters car ($23,000) for $1200 down and $400/mo X 36mo and she agrees to buy my car($7500) (to be subtracted from the price of her car) leaving her with no payment. The contract includes agreement to each drive our original cars until delivery of her title. We thought her estranged husband needed to sign off . Unfortunately, only 1 signature was needed, so he sold her car. The new owner titled and took possession of the car. My contract is notarized and precedes his sale by several weeks. I have already paid her a total of $1600. Does my contract/bill of sale entitle me to the car? If so, can I ”repossess” and then file suit, or do I file first and risk them hiding the car?

Paid for a car but Bill of sales states you did not pay.
I bought and paid for a car with cash. Had a lot going on that day I did not notice that the bill of sales state I owe a balance instead of saying I paid for it. Less than 24 hrs later car stop working. tried to contact the dealer he told me he can’t do nothing for me however he had told me before I signed the paper work that I have 3 days to return the car if anything other than the water pump is wrong with the car. The car has been sitting in my drive way for over 2 months due to me not being able to fix the car. So I bought a car and never drove the car. I understand that was stupid of me for not checking. I received the Title to the car 3 weeks later. Now he’s trying to suit me to get pay again. I don’t have any other proof that I paid him other than the title that I have received for the car. What are my changes of winning this case and do I need a lawyer. Thanks