Xoutpost.com - 2 Questions about Intake Tubing E70 N55

I have an air leak at the connection where the mass air flow meter air duct connects to the bottom air duct that (I'll just call it what it is, the turbo inlet pipe). I have it circled in red in the pic, at the front passenger side of the engine. The hose clamp is bottomed out but it doesn't get tight, and I can wiggle the clamp and connection around. I am wondering if there's supposed to be a rubber gasket/seal in that connection, but I don't see anything obvious on the Real OEM parts diagram. If there's not supposed to be a seal/gasket there, how have others fixed this leak? It's a stupid design with 2 hard plastic pipes connecting, which is going to fail over time with heat. I see there's a metal sleeve inside the turbo inlet pipe, so I'm thinking I'll find a different hose clamp for the time being and just clamp it as tight as I can.

Second question, I am doing a smoke test, and would like to know what size rubber coupler will fit on the end of the mass air flow meter duct where the airbox connects. I've tried using a rubber glove but they tear too easily. I have an old boost leak tester I can use for the smoke test, but just need to know what size coupler will fit there. I have one that's oval, so it's hard to measure, but I want to say its like 3.75" and it feels too loose to use.