Does anyone have an owner's manual that details how to remove the piece of plastic behind the air intake box? I am trying to remove the restriction caused by this piece in order to pull more air through the windshield vents as the tiny hole provided doesn't really do much. Any help is much appreciated.

Just go here;
https://www.northamericanmotoring.co...ead.php?t=4133
Also in the upper right there is a search engine.

I've always been a bit suspicious of the punching holes or removing this piece. It does isolate under hood temps and fumes from the air intake for the HVAC system.
Heat and smell is not what I want to suck into the cabin of my car.

thanks for the link. new to this whole thread posting thing. the instructions were perfect. more flow...and no added smell in the cabin.

Just a note that removal or alteration of this plastic piece is not legal for SCCA Solo II stock class events.

For street driving and track use it is fine.
Don't forget to store it in a safe place where you can find it.
I've got a garage full of spare OEM MINI parts now.

i agree, especially if you've got CO in those fumes. soon i'll cut an oblong hole through both walls then seal the gap with soft silicone foam so there's no path into the cabin.

I believe cabin intake is only on the other side. Thats where your cabin filter is.

If you look closely you'll see that both plenum areas are connected. It's where your brake lines run from the master cylinder to control module on the US passenger side.

Oh, you're right! I guess that cabin filter works good, I've never smelled any fumes in two years.

It's what you can't smell that'll kill you.

That said though it is just my opinion