Child Support Question...?

Hi! My child's father is in arrears. So, next they go after assets. And that would be his car. But customer service had said the car is in his spouse name. Yet he is not married! I look online in the state of Missouri and found no marriages. My child has not seen her father with a spouse neither. If you could be so kind to tell me what's is the situation going on. Also, what should I do? Thank-you