As I said above, either the MicroCAN or Hex + CAN will work with your car.
I can appreciate that funds are tight but perhaps I could offer a word of advice - Most UK authorised sellers still have stock purchased when the $/£ was better, when they have to re-order they are going to get a kick in the nuts so if you could afford it sooner you may well find yourself saving a packet.
Stu.
A4 3.0 TDi S-Line Quattro, 7 Speed S-Tronic, Quartz Grey, 19" Twin Spoke Alloys, Alcantara with Silver Stitching & Heating, Nav High, B & O, AMI, DAB, Parking Advanced & Rear View Camera, Advanced Keyless Entry, LED Interior Light Pack, Hill Hold Assist, Heated Electric Folding Mirrors, Through Load.
Previous MY11 S3 Sportback Black Edition, S-Tronic, Ibis White.