IO,
They don't do ad-hoc rental.
As the web site says
here "Member Pilots enter into a One year Usage Agreement with FreeFlight Aviation Ltd." and "Flying Bands are available to suite (sic) all, from as little as 25 hours a year up to 100 hours"
Ian is an occasional poster here and I'll point out this thread to him, but for detailed queries just mail him - his address is on the web site and he loves to talk Cirrus!