How to buy tickets for Spa Six Hours Classic?

[pasmith73]

I would like to attend the classic Spa 6 hours this year (15th-17th September). The website is now live and says that you can buy tickets on the gate, however I'd be happier buying them online and knowing that I've got them. When you open up the online ticket site, it shows everything as sold out, but I'm sure this has not been updated since last year's event. Do you know when the ticket site goes live for this year's event?