The rule clearly say " velocity stacks, ram air or crowl induction are not permitted unless fitted as original equipment. Air intake hoses, tubes, pipes resonators, intake mufflers, housing etc. located ahead of the air metering/measuring device may be removed or substituted " in the CRX case and some Honda you are fitting the cold intake in the ORIGINAL location the same way that they are provided from factory, note if you look at the CRX factory system it is in a way a cold intake system because the unit start from behind the bumper ( factory ) and goes to the inside of the car via a opening to the air filter and back to a tube to the Throttle body, so when you are installing an AEM cold intake you are using the same basic and the same opening as the factory and that is allowed by the rule.
Again I may be wrong but that is how we read the rules in the SE devision and almost all the CRX in this region runs cold intake and never challenged by any other driver even at the ARRC.
Note: You said "could not put anything on the underside of the hole" I think that is a wrong statement from the Tech because again CRX had a factory pipe running in that hole, and any Tech representative should know that this is a wrong statement unless he did not know that CRX came factory with a pipe going via that hole, your only source and your only tech info should be the GCR and from the GCR.
Again I may be wrong but that is how I read the rule and I ran in the last few years over 30 races and never ever got protested for any reason.
Louis