http://www.ppcmag.co.uk/ppc-in-the-park.html See the tabs in the upper middle of the page; left hand one for buying your ticket.
There doesn't seem to be an official club stand organised by the RTOC this year for this event but I spoke to the organiser today and she said that she would do that for us.
Any RTOC member has only to buy their ticket using the on-line form and she will arrange for you all to park together in a RTOC designated parking area.
The event details can be seen at the above link.