Well, I spent most of the day trying to get tickets as an ACO member.
Unfortunately (yet again this year!!) the ticketing web site either wouldn't let me complete my order or crashed when I went to check out. I am currently ticket-less, the bar-stewards!!
The main reason for using the ACO is to get grandstands tickets in 17 or 18. It would seem from the ticketing web site that there are currently none of these grandstand tickets left.
Have emailed the ACO to complain & they've said they'll get back to me. I don't hold out much hope.