Most credit cards are unsecured debt. This means your credit card debt is not tied to a specific asset. Therefore, they cannot seize your car to pay off a credit card balance.
However, if you used your credit card to finance the purchase of the car itself (a car loan) *through* the credit card company or used the credit card to obtain a loan that is secured by the car, then the credit card company *could* repossess your car if you default on the payments. In this scenario, the car acts as collateral.
In short: Standard credit card debt doesn't allow repossession of unrelated assets. Only if the car is specifically pledged as collateral to secure a loan obtained via the credit card could repossession occur.
