The bentley manual costs a fortune and is written for the American market. Many engines and gearboxes are not covered by it.
If you know where to find, ahem, 'dodgy' copies of things then search for ElsaWin on the net. This is the workshop manual Audi use in their dealers. Very comprhensive. Alternative people flog it on Ebay for about tenner for the full lot covering every VW/Audi/Seat/Skoda made since yonks ago!