AutoNation Mobile Service makes updating your payment method a breeze.
Updating the billing address for payments can also be managed by following this article
Simply login to your account here and follow the steps below.
Step 1. Navigate to the "Edit Account" page.
Step 2. Scroll down to the "Your Payment Methods" section.
Step 3. Select the payment method you wish to set as default or delete, or select add a card to add a card.