Im on 98000 miles on a 54 plate ibiza 130, Ive had it since 82000, and its never missed a beat, only problems so far was the sump plug that had been helicoiled by previous owner and was leaking, and I've put a new sump on now and it leaks round the sump now, but i'll have another go at it soon with some decent sealant should sort it. I did use sealant but doesn't seem to have worked. Oh and im going hybrid turbo with it soon just need clutch sorting then can fit the turbo and get it mapped. I'm hoping to have it upto 150,000 miles with no issues running 220 bhp, And even then I think the only weak point is the head gasket.
Same problem with my tollie PD130. Sump plug was leaking like a pig. Put new sump on with proper VW sealent. Had a bad leak at gearbox end (probably hidden bolts not done up as tightly as I would have liked), so had to redo it all....
Still going strong at 129,500 miles (24,500 miles with remap). Just had to replace the pulley on the alternator as it was making a horrible grinding noise when turning the wheels at idle. £45 at local specialist.