If possible I'd request a VCDS scan of the car, so you can check error codes, or perhaps find someone with VCDS to scan for you prior to purchase.
Things to lookout for, rusting front arches.
Look to replace camfollower, 28 quid part, dump valve rev g, 25 quid part and poss. PCV similar money. All very cheap problem areas other than the arches, but VW should cover these outside warranty.
