basically she is an adult now and the car payment agreements is between her and her father. The more you try to fix or speak out against the situation it will only cause more stress and a possible wedge between you and your husband. In fact the more you show of you dislike for the daughter will cause problems between you and your husband.

My suggestion - he already knows how you feel so now its time to let it drop and become the responsible, and respecting adult you are - When it comes to family situations where you will encounter her be a responsible, respecting adult - that is don't get baited into fights or discussions about her and if she tries to start something with you, you are older then she is act it by not falling into her baitng - don't react, just keep everything on your side respectful. in time she will either change her behavior or choose not to be around you because she cannot manipulate you like she can her father. What every one else in the family will see is that you accept his side of the family unconditionally and the most important relationship here - you and your husband - will stay strong and intact. Thats what really matters here not your husbands and his daughters relationship thats for them to deal with.