Can a credit card company take your car if someone else already has a lean on it?

No. Only a bank, court or dealership, is allowed to repossess the vehicle. In which if the car is yours and you have the title and proper documents proving that the vehicle you bought is yours. And if that "someone else" is not a spouse, Than no they are not allowed to take your car as it would be classified under auto theft. My recommendation is to alert the "credit card company" That the vehicle is yours and they should go after the debtor. The person whom sold it to you should of made you aware of this debt.