Welcome to the forum Dave
Lots of things to look out for, main one being looking through invoices and make sure it has had regular oil services, DSG should have been serviced every 40k miles, make sure cambelt & waterpump have also been done around the 40-60k mark. Check sills and arches for rust. Easy enough to tell upon inspecting these whether they have been well cared for or not. Well worth looking over the forums and facebook pages for an enthusiast owned one before delving into ebay/autotrader etc.