Technical Fiat grande Punto making rattling noise

[Tigermsn]

Hi, my 2007 reg fiat grade Punto, roughly 70k started making a rattling noise (attached) recently. Only makes the noise when the vehicle is moving on road (e.g. no noise when engine is idle). It tends to increase as car accelerates, but still there when I'm going downhill (with no gas). The noise is always there at different speeds, gears and only disappears when clutch is fully down.
Took it two garages, one said the noise is from gearbox and other said it perhaps from broken flywheel. what could it be gearbox or fly wheel? Flywheel is perhaps cheaper to fix but needs urgent attention. How can I rule one of them out?

 

[GrandePunto PL]

Bad management on your side. Took it to 2 garages and you declined repair/diagnosis twice?
You should drop the gearbox ASAP and let them inspect deeper.
It's probably a gearbox (input shaft or differential if the noise changes during a turn left/right) or clutch (not "flywheel").
First rule out the wheel bearings and axle CV joints (those make noise under the load). Engine as a last resort (crankshaft end-play etc.).