Well, thanks very much guys. I have been trying to resist lowering since getting the car 2 and a bit weeks ago. Thanks to you all, I am now looking at springs and will probably buy a set tomorrow. I had Weitec coilovers, Eibach ARB's, Whiteline ALK etc on my previous A3 and it handled VERY well, better than stock GTI, however stock GTI is miles ahead of stock A3 Black Edition (IMO).
I'm insured with VW as they were the cheapest and unfortunately they won't cover any mods, so I am going to call tomorrow and try to convince them it's fitted by dealer so it's ok to declare lol...