Check out the Scorpion website, look under challenge events, and see the regs section. I have Scrutineered for one of the Clubman events, and the level of prep varies hugely. From people who have made little effort, to those whose car is spot on with all the boxes ticked.
Id say make every effort. At the end of the day, the challenge events are serious business, the insurance and regulations are in place to ensure everyones safety, and should be adhered to.