It did tell you under the ticket section and then view account menu on the website. There was a drop down saying Auto Cup.

But, this has now gone. However, on the same section, if you look at account history our Mansfield tickets are all listed.

I guess I remained in the AutoCup by default.
I cant see how you get out of it though!

If your friend sorts the account and you are on his family and friends the information might be on his account.