If you can't pay off a car and the bank repo's it do they come after you for the money or just take the car?

Depending on your income situation and asset situation, then they may attempt to recover ALL remaining monies owed. If they see they cannot get money from a stone and you have NOTHING to sell to make good, then they often count their losses and just take the car, damage credit, and have a collection company harrass you. If you have home and/or assets or other cars, they will seek the payment for remaining owed money.