Just adding a further "thank you" on this, as it DID turn out most useful. Done this twice so far and it was an ¤¤¤¤ on both occasions! Like yours (stef) my intake pipe is now more gaffer than original (I could replace it with a generic halfrauds tinfoil one, but I've seen those unwind at an alarming rate before - i reckon a couple of tiny vacuum leaks drawing air from the engine bay to the filter won't matter), and now I've got the added, sexy, concours-winning bonus of the airbox itself being sealed up by it.
Yep, those damn torx screws and their stupid location / inability to be completely removed. One of them is almost completely drilled out, and impossible to put back in place without a little cross-threading with the tools I had, so I've left it standing a little proud (it'll still stop the box from falling out completely and the filter unsealing) and secured the box fully in position with the other one and half a roll of tape, as the only thing on there it would stick to was itself.
Note to self: Next time I have to do this, fully clean and de-grease the outside of the airbox before re-assembling, or at least remove whatever alien-technology coating was preventing even duct tape from sticking. Also use a mini-ratchet with a high quality torx bit, and maybe make use of some glazier's putty to try and restore some kind of screwability to the bolt head, given that it can't be removed. That or find a scrap housing cover that, somehow, hasn't got ruined bolts.
What is it with Renault and using Torx bolts in completely unsuitable places? I've had to replace all the pencil
securing bolts with hex-heads as well, as I damn near couldn't get the original ones out after the first go and certainly didn't fancy screwing them back in a second time... (plus it was the devil's own job keeping hold of them whilst inserting or removing... one disappeared off into manifold land for a while and was only later found having been shaken out onto the driveway by the bump of the kerb)