Hi Stephen, Having just bought your Audi A4 2009 2.0 Known as B8, it takes a while to familiarise yourself & get to know what is fitted, what to look out for etc. In Australia, we don't have "59 Plate" - just Build Plate Month/Year & Compliance Plate. I don't want to alarm you, just inform, so here goes....
In addition to Gareth's advice:- Check if it has had Timing Chain Tensioner Revision already fitted. There are a few more things to watch out for, just like any used car on the market.
If I remember correctly:- there are reported cases of the old Timing Chain Tensioners failing on some 2.0 Engine Codes. In Australia, there's a site for reference, with Detailed Reviews, Complaints, Recalls for various Makes & Models. Check with your Audi Dealer. or a respected Independent in your area. (I've seen many Audi Owners remain sceptical of what previous owners say, plus what Dealership Service people say, when asked about "any known problems") http://m.australiancar.reviews/reviews.php#!content=recalls&make=Audi&model=A4&gen=37&pno=0
I have 2010 A3 8P 1.8TFSI EA888 CDAA 6MT. (Similar Engine, with Timing Chain)