Generally, divorce cases involve restraining orders that prevent the sale and/or disposition of marital assets. If you have a restraining order prohibiting the transfer of the car then you cannot trade and/or sell the car without a new court order that gives you permission to do so. If your wife approves of you trading the car then you can have her signe a consent order giving you permission to trade the car.
You should consult with an attorney as soon as possible. There may be other considerations that you should make prior to trading the car.
Sign up to receive a 10-part series of useful information and legal advice about the divorce process.