Glad you posted this Maze.
I attempted to place an order last Thursday which was around $100. I entered my billing/shipping addresses as usual, entered card info at the bottom, then proceeded to the "securecode" screen. Rockauto is the only site I've ever used online which requires it, and I have done so with 0 issues for at least 15 orders prior. I hardly ever remember the password for it, so I reset it which went smoothly. On the next screen when I attempted to enter the new password to complete the order, it bounced me back to my cart and gave a "cannot process your order" type screen, suggesting that I contact my bank to remedy. (PS, if you enter the wrong password, it says "try again", so this wasn't a wrong password type issue)
I called my bank, they told me they have no control over Mastercard's securecode besides checking the password record, and whether the card is currently active or locked. They said they see no issues whatsoever. So I called Mastercard and went through their obnoxious 100% automated "customer support" line. At one point it asks to enter the Mastercard card number, which I did, next thing I hear is ringing - they automatically transferred me back to my bank. Who again told me, they can't do anything. I went through this process 3 times (one time I even spoke to an actual human resource at Mastercard, who also transferred me back to my bank without warning! Wtf?!)
I attempted to call Rockauto to see if I could place the order via phone, but the person there said that there is no "roundabout" way to do it, and that they use the same order processing system that's found online - which would eventually ask for the securecode.
I'll try to place another order on Thursday, but unfortunately Rockauto lost my order last week because it was for things I needed urgently. I'll report back this Thursday whether or not it worked for me, but last week both my bank and Mastercard seemed to be pointing at an issue with Rockauto's order processing system. I also googled it and it seems to be a somewhat common issue with securecode on Rockauto... hopefully it can be fixed if not done so already.
Thanks for any help you can provide @RockAuto