All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If you bought the car through the bank then it was an obligation on you to know the reality of the transaction and how the bank bought the car for you. That is because non-Islamic banks finance the car for the customer and increase the price for him without the bank actually buying and possessing the car and then selling it to him. The reality of this transaction is a loan with interest. The bank pays the price of the car for the customer and then obliges the customer to pay back by instalments with an increase in the price because of the delay in payment, and this is nothing but usury and interest.
So whoever has carried out this transaction has to sincerely repent to Allaah as he has indeed committed one of the great major sins by which he deserves Allaah's curse and anger.
For more benefit about getting a loan with interest in order to buy goods, please refer to Fataawa 88400 and 88238.
Allaah Knows best.