Now the B.S. begins

You let the car go when you relocated without it. If you don't have the finances to legally fight this with a good lawyer, let it go. You will never get that car back, but the bandaid will be pulled off quick.

Honestly if the dectective said you were legally 1/2 owner, and she sold the car for $6K, you are owed $3K at minimum. The detective does not run you. A good lawyer would get the cash back or charge her but chances are the car's gone regardless. So do what you will.