The talk of airboxes and their complex internals on F3s reminds me of the 1984 controversy at the end of the Euro F3 series.
I don’t know if I’m remembering all of the details correctly, but the story as I recall it, concerned the Coloni entry for Ivan Capelli (who won the series). Johnny Dumfries (who won the British series that year) was in with a chance of the Euro title too, but had an “off” in a late-in-the-series round.
Capelli’s airbox was thought to be illegal (and I think had been ‘dissected’, revealing something possibly untoward/clever/sneaky inside) and was retained by the FIA (or possibly the local sporting authority) for further study or as evidence or whatever. Whilst in their custody, the suspect item unaccountably disappeared… and there were no further actions or sanctions.
Dumfries lost points that might have secured him the title having his 'off' whilst chasing an ‘illegal’ car; without that extra pace, he wouldn’t have had to push so hard to stay in touch. I don’t doubt that similar things have happened before, and I don’t know if the legality of the car in the preceding rounds was questioned.
Does anyone else recall this, or have a different take on the episode? Or can show us what actually goes on inside such an airbox - or what Coloni might have done to theirs?