How would the co-owner of a new car take possession of the vehicle for failure of the other co-owner currently in possession to maintain insurance?

To take possession, you MUST be named on the TITLE as co-owner. the LINHOLDER will wanting to be sure the car has the required ins. coverage. IF you are on the LOAN as co-buyer, you will have to make the loan CURRENT if in default. It would work out better if you contacted the LEINHOLDER for state specific advise on the matter. If you are NOT on the loan, it could be repoed for 3rd party possession in your possession.