Every few events, someone rocks up with a factory special edition — a performance trim, a limited-run model, something with a badge that isn't quite "base spec" — and asks me whether it's still eligible for EMMA's OEM class. The short answer is usually yes, but the rule that decides it trips more people up than they expect, and it's worth understanding before you build.
What "OEM" actually restricts
In EMMA Sound Quality's S (Skilled) and M (Master) categories, the OEM sub-class exists specifically to keep the playing field level against Unlimited, where cabin trim can be cut open and speakers relocated almost anywhere. OEM pulls that back hard. The rule for S class reads: "In the Cabin area, only OEM speaker locations and/or grilles available are allowed to be used." M class carries the same restriction, minus the grille allowance.
That's the part people plan for. The part they don't is the second half of the rule, which deals with what counts as "OEM" in the first place: "No special edited car-models from 'tuning companies'; special editions from initial car-manufacturer is acceptable."
So what actually qualifies
Read plainly, that line draws a clear line between two kinds of "special edition":
- A factory special edition built by the car's own manufacturer — a manufacturer performance package, a limited production run, a higher trim level sold through the dealer network — is fine for OEM. If that trim happens to have a factory speaker location your base-model car doesn't, the rule explicitly allows you to use it: "If a higher OEM-trim level as the competitor's car has other/additional speaker locations" than your own car, you can still use them.
- A car that's been reworked by an aftermarket tuning house — a third-party body, interior or electronics specialist with no factory mandate — does not qualify as OEM, even if the end result looks production-grade and even if the speaker locations themselves weren't touched. The rule is about who built the car, not how tidy the install looks.
In practice, this rarely matters for the kind of daily-driven hatch or sedan most Entry and Skilled competitors bring. It starts to matter once people go shopping for a "better" base car to build OEM into, and a heavily tuner-modified example looks like the easy win. It usually isn't — not in OEM, anyway.
Where this leaves your build decision
If your car is already a genuine manufacturer special edition, you're not disadvantaged — build to the OEM cabin-location rule the same as anyone else, and the extra factory speaker positions your trim came with are fair game. If you're shopping around specifically to gain an edge, that's really an Unlimited conversation, not an OEM one — see our breakdown of OEM vs Unlimited install categories for where the real freedom (and the real cost) sits. And if you're still working out which Sound Quality class fits your experience level in the first place, start with EMMA Sound Quality classes explained.
One more thing worth flagging before you commit to a car: the cabin speaker-location rule interacts with your actual install work, not just the car you chose. Our key EMMA install rules page covers the installation side of OEM class in more depth, and if you're starting the build from scratch, our general guide to car sound upgrades is a sensible place to begin before you get competition-specific.
When in doubt about a specific car — especially something unusual like a grey-import special edition — ask before you build, not after you've been judged. It's a much easier conversation at the entry list stage than at the car park on competition day.
Written by Pete — Integrated Audio
Pete is the founder of Integrated Audio and a Certified International EMMA Head Judge, judging EMMA Sound Quality and Installation competitions in Australia and internationally. He writes from the judging side of the table, drawing on hands-on experience building and installing HELIX, MATCH and BRAX car audio systems.