Golf IV / Jetta IV :: Exhaust Keeps Leaking - Fumes Coming Out Of Engine Bay On Cold Starts

Since day one I've had an issue with the exhaust leaking on my car, right at the flex pipe before the cat. I have replaced it at least 5 times in the last year. Every 2 moths or so it tears the flexpipe right in half, like it's literally in 2 pieces when I take it out. So, I thought that maybe the factory dogbone mount was old and weak, causing the engine to move around more, therefore tearing the flexpipe apart, so I got an new dogbone with poly bushings to combat that. It did reduce engine movement, but the exhaust kept breaking at the same spot. Then I thought that the metal was weak from it being welded so many times, so I got a new downpipe with the cat on ebay for like 150 CAN, and put a new gasket on, and now it still leaks...

Only thing though, is that this time on cold starts (as it is winter, so around -25 celcius) its really REALLY loud, like the exhaust sheared off right after the cat. However, after a few hours of driving it seems to get quieter at idle, but if you give it a little gas, it is quite audible. Also I can see exhaust fumes coming out my engine bay on said cold starts, however if I get down to ground level, I can hear it plain as day right where the pinch clamp is that connects to the catback part.

So, my theory is that, cause the bands on the clamp rusted out so my dad just put those u-bolt muffler clamps on there, which I can see an opening in the clamp, even if they're tight, until the exhaust gets hot and expands, kinda making the seal tighter but not air tight like it should. So maybe that clamp isn't doing it's job anymore and I just need a new one. OR it could be that that stupid flex pipe is broken again or that the bolts holding it to the manifold aren't tight, which that can't be cause i got them pretty snug on there. I'll have to take a look underneath again, see If I see any carbon on the exhaust, which would mean a leak, but I checked a few weeks ago and it was shiny metal, no signs of any leaks.

Car is an 04 golf with the 2.0 engine code BEV if that makes any difference. I double checked and NONE of the hangers are broken, and it's held in the right spot as it should, there looks to be no force exerted on the flexpipe at all when installed in the car, so I'm really confused.