digging a bit deeper, from SAE J1492 ...
"If a vehicle has a single operating mode, the results obtained by using this standard shall be reported. If a vehicle has two or more modes of operation that change the sound emission of the vehicle when tested according to this SAE Standard, the manufacturer may identify to the customer the modes which are used for compliance assessment. Any mode that can remain enabled through a power on/off cycle shall be included in the modes identified for compliance assessment."
Technically, any mode that the OEM designates as being applicable to the test shall be included in the test. That list of "approved" modes MUST INCLUDE any mode that stays engaged after a power on/off cycle. But it does NOT mandate that all modes be tested, so the OEM has the ability to choose which are included and which are not. That way, they are not accountable for modes which they do not intend to be complaint. What this means is that as long as Hyundai doesn't include the noisy "N" sport mode in the modes which are retained through a power on/off cycle, they do not have to be included in the sound assessment test. BUT, that also means they are not certifying that particularly noisy mode as being street legal.
The driver admitted he was in the sport/track mode on the street (can clearly be heard saying so in the video). When this owner was driving in "N" mode (the sport/tract mode), he was likely in violation of the law because Hyundai did not include that mode in the on/off retention modes as far as I can tell. Hence, Hyundai is not at fault; the driver is.
The officer was not in error here. The driver admitted he was driving in the noisy mode. I've researched the owner's manual and supplement and as far as I see, the noisy mode is NOT certified for street use; I can find no mention of the "N" mode noise being certified as street legal. IF someone can find a direct reference to the "N" mode being part of the street legal scheme, then that would make things different. But given the text of the owner's manual, and statements from the linked article, I suspect the "N" (sport/track) mode is NOT included in the power on/off retention on purpose, and therefore is NOT required to be certified. But that also means it's not legal to operate in that mode on the street.
Here's the reality of what needs to happen:
- the cop needs some counseling; it's not his job to be the judge and jury here; enforce the law and the it play out in the legal process
- the car does not need to be modified as the cop claimed; it only needs to be tested and operated in the certified modes for compliance
- the driver admitted he was operating the vehicle in a mode which is not certified for street use; he earned the citation and should have to pay for the ticket
- the CA code needs updated to more clearly define what is and is not acceptable