In most cases, an individual receives no ownership rights when they assume the role of a co-signer. In the case of a car loan, the co-signer would have no legal right to use the car without explicit permission from the primary borrower. Their only responsibility is to guarantee the loan payments in the event the primary borrower defaults. The one exception is a co-signer on a mortgage. In this case, the co-signer's name appears on the property’s title, which means they retain some level of ownership status.