There is a tiny little gap between the connector pipe and the airbox. I was thinking about getting some alu tape and just going around the join to make sure it's pretty sealed.
It's a bloody tight fit, as the coolant pipe from the radiator is in the way. I'll take some photo's tomorrow and show just how much of a squeeze it was. It's definately improved performance. Is it worth diconnecting the battery and making the ECU re-learn with all the breather mods completed now?