spam_face - first of all you have a debt - let's say £1,000 on a credit card.
You can then transfer that debt onto another card offering you a good free transfer time limit - some are up to sixteen months. There will be a fee, around 3% to transfer.
If you wish to move that £1000 into your bank, then that will be seen by the credit carc company as a cash transaction, which will attract their seriously high cash interest rates, wiping out the benefit of the initial transfer deal. The credit card companies are not going to allow you to loan their money to your bank for minimum rates, otherwise we'd all be doing it!
Ideally, you need to ensure that that the free balanace transfer refers to cash and purchases - which most do.
Then buy your car with your credit card, and mame sure you pay the balance off within the time - not sure, but you may find that failure to do that will render you liable for interest on the whole transfer amount, not just the remaining balance.
A final word of cuation - make sure that your payments reach the bank on time every month - you need to pay in at least ten days before your stated due date if paying by transfer, or at least two days if paying in by cash. Failture to get the payment in on time is your responsibility, and the company can and will cancel your free transfer agreement and sting you for a fortune!