If I understand your facts correctly, you and your ex purchased the car while you were married. You aren't a co-signer for the loan, you are directly on the loan and can demonstrate that you made most of the payments.
When you are in the midst of a divorce and need clarity you ask for temporary orders. When you are divorced and a decree has been entered, then the decree will say which of you takes what property, and the debts associated with that property.
WA also has replevin laws (look at Title 7) that allow a person to state a claim for immediate return of personal property. There is a short procedure to get the Court to give you an order allowing you to get the property back. It also allows you to ask for attorney fees and costs to be paid by the person wrongfully holding on to your propery, if the judge thinks that is appropriate.
If you are on the title to the car and on the registration and have insurance for the car and are making the payments, then there isn't any real basis for him to refuse to hand it over. But WA frowns on self-help. Your rights and your ex's rights are substantially equal until a court says differently.
Hope this helps. Elizabeth PowellAsk a similar question
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