OEM system still going strong on mine at 105K.
Leistritz used to make the OEM exhausts for VW, not sure if they still do.
If you want to keep it OEM, then replace the relevant silencer with another OEM part is my advice. End to end, it's hideously expensive unfortunately. Last time I enquired, it was about £450 for the rear silencer, £350ish for the middle silencer, plus another £600-700 odd for the downpipe/cats.
How bits of pipe could ever cost £1000s is a mystery to me, but it's the world we live in unfortunately.