Have you tried calling the company you need to make payments to..? They might take a credit card payment over the phone (you just give your card number), or if they have a website, you can create an account at that website & make payments there. :)
You need to contact the auto company to ask for their checking account. Autopay is an automatic direct pay that can be covered from the minimum pay each month. Make sure you get the right number before transacting money.