My STBXW bought new white SUV but is leaving it with a friend. The divorce isn’t finalized yet and she’s making me pay child support in the interim.

I know she makes more than me. But how do I find out that she purchased another vehicle for herself. I want to bring it up to the judge that she purchased a new vehicle while claiming that she isn’t making enough and having me pay child support.

How do I also get her to admit or verify her income when half of it is cash and other half is check?