My 2001 Golf flex pipe (turbo to the cat) was leaking so bad I thought additional brain damage might occur. I also had a leaking steering rack so needed to drop the subframe which gave me access to the piping without having to work around it.
I ended up getting the flex pipe section from ID Parts... it did however take a bit of doing to get it to fit. The connection to the turbo pipe (the flex fitted over it) was made tight by some heavy duty clamps (also from ID Parts).. buy two. At the other end...the fitting to the cat required some welding as 15 years of corrosion made some cobbing a necessity. I think the key to this repair is knowing that you may have to be ready to connect things in a way dictated by necessity...and a welder is a great help for this.