For the GT2 class using the Sprint 2 it might be worth allowing clamped ali hex's too? Here are my thoughts/suggestions anyway, building on the rules from the last race..
Part allow List
HPI UJ's - http://www.hpiracing.co.uk/piw.php?partNo=86198
RPM Ball Cups – 100’s on ebay
6mm HPI Ali Hex's - http://www.hpiracing.co.uk/piw.php?partNo=72036
Any wheels nuts
HPI E10 foam bumper (Fills the shell better) - http://www.hpiracing.co.uk/piw.php?partNo=6279
Use of bumper on the rear (again use an E10 foam)
Choice of shells -
BMW M3 - http://www.hpieurope.com/piw.php?lang=en&partNo=17548
Corvette C6 - http://www.hpieurope.com/piw.php?lang=en&partNo=17503
Porsche GT3 - http://www.hpieurope.com/piw.php?lang=en&partNo=17541
Ford GT - http://www.hpieurope.com/piw.php?lang=en&partNo=7495
All shells to use this wing to standardise –
http://www.hpieurope.com/piw.php?lang=en&partNo=85288
HPI +3 front and +6 rear offset wheels, open choice of colour/design as before. The inserts could do with being thicker though if we can get some, we only wore our tyres on the outside edges near the tyre wall with those thinner inserts. There was too much of an air gap I think and the main patch of the tyre wasn’t worked as much, just collects pickup. Not sure how everyone else got on? Thoughts?
The chassis must be completely stock and built as per kit instructions. Only exceptions are general shimming, lubrication and mods to battery holder parts for QR battery strap. EG no titanium/ali screws and servo horns, no hard diff grease/sealing and turning the diff into a near spool like affair ect ect.. Everyone has the same ESC and motor whatever brushless solution we go for. Only 1 shell to be used in the race.
I'm open for debate but these are just some of my ideas. My thought process was to improve the weak points on the car from last time (mainly ball cups) and leave little room for super ninja performance sneakery. We all try it

. With the cars on similar pace the race will come down to teamwork, battery changes, driving and putting the new tyres to good use.
Although I suggested a GT1 & GT2 format to accomodate the idea of other TC's, on reflection I vote we stick to the Sprints. To be fair I dont know of many high spec touring cars that are built to last, they are built to be fast over 5 minutes. Aluminium/composite outdrives would get raped in about 2 hours! It will be so expensive to run somthing like that for 24 hours, the spares costs from most makes would be enough to make you cry.. And from likely part failures (mainly ball diffs/spools) the Sprints could beat them anyway by solidering on, which would be super embaressing

. I imagine most of the teams will want to come back too, taking up most if not all the rostrum space. Any new teams wishing to enter, it would still be cost effective with the Sprint 2.
Hope these suggestions arent taken the wrong way, as I said before the event was epically brilliant, all the teams were great and John should be knighted or something! These are just my ideas to possibly help make the next one even better.