Not really, when was the last time someone at scrutineering pulled up a competitor and said 'why are you in base modified, you should be in super modified'?  Although scrutineers can check eligibility I would expect that their task at a sprint event is mainly to check conformance with the AROCA supp regs and safety aspects of the car.  Like any other class (sprints or otherwise), the best eligibilty officers are the other competitors in that class, you can bet your bottom dollar if someone is doing something to their car that is giving them an unfair advantage, then it will soon be known!!

If it really worries anyone though, I will put my hand up as an eligibility officer (and anyone is welcome to inspect my car for eligibility!!!).

Wouldn't a Group S car fall into Super Modified class anyway (at present)?  You run standard brakes on those things don't you?

By my reading, engine internals, gearbox internals and headers is one modification.  Springs, sway bars and dampers is a second.  You run race tyres, so that's all you're allowed.

You guys run standard brakes and retain interior fittings (unless it gets in way of rollcage, and certainly not hollowed out or lightened, ahem) don't you?

Someone correct me, but that would make it Super Modified.