Andrew poses this question in his new "Wheelspin" e-magazine. My solution is to create a class 9. This would basically be for "Sporting Trials" cars with lights etc for the road. eg:- Cannons, The Dingo etc. Class 8 would remain for modified Dellows, Buggys, true specials, Trolls (and Dudley). The idea is that you would need an ACTC/MCC certificate to compete in class 8. This would be granted on the basis of your car being truely suitable to drive on the road and not of Sporting Trials origin or intent! Sticking my head above the parapet I volunteer to chair the eligibility committee.
You can throw the most severe challenge at class nine (restart on the slab at Simms?) or give them 20 marks penalty before they start an ACTC event.
If we want to limit the number of classes to eight then do away with class six. Any Beetles with a standard single Solex carb and an engine capacity of 1600cc or less go to class four. Over 1600 an/or non-standard carb go to class seven. This relies n the honesty of the driver just as it does for 1300 Beetles today in class 4.
Michael