Duing period of separation with husband would it be okay to leave with a car that he is paying on

I came into marriage owning (paid for) vehicle, as did husband. We traded my car in for another that has payments on it. Both vehicles & insurance, per husband, were put in his name. He has been paying payment and insurance. To get out of a bad situation (agreeably bad by husband, but he is not willing to sign even a separation agreement) - would it be ok for me to leave with a car until agreement reached? He says I can't take a vehicle when I leave or he will report it stolen. I don't have key to paid for car that he drives. I only want a vehicle, either one, nothing else. No kids involved.