I made this a few days ago and fitted the thing today. It aint pretty, but it gets rid of that silly plenum with all its convoluted chambers and noise suppressing twists and turns. Cost me about 50 bucks, including the heatproof paint. It's 90mm PVC rainwater pipe...completely airtight, the breather hose is connected and the thing sucks in air like crazy. It all fits like a glove and is as solid as a rock. I'm happy with it. And seeing as I spend my time in the car driving it rather than gazing like a schoolgirl at the engine bay, the faact that it is a bit lumpy doesn't bother me a bit.