Ok after a bit of digging i found this. From what I understand that means mine SHOULD fit without the need for spacers. Maz / SLick / Olaf - the links on here might be of interest to you too.
http://www.bira.org/info_main.html
System 1 for the TT and Mk 4 Volkswagen
Uses Porsche Boxster 4-piston monobloc caliper over the 2000 Audi TT 312x25mm rotor. Fits Audi TT, Mk 4 Volkswagens with the 5x100 bolt pattern, and any other car that can accept Audi TT brakes bolt-on. Fits under the factory TT wheels.
http://www.bira.org/info_main.html
System 1 ONLY
Tested and Acceptable:
* Any wheels that fit over BIRA System 2 brakes (see below)
* A8 17" five spoke wheels. More information forthcoming.
* Audi/VW Tango wheels, 16x7 ET45. "...fits fine, but the stick-on wheel weights MUST be mounted to the far inside of the wheel."
* 1995 S6 Avus style stock 16" wheels
* 1993 S4 stock wheels, 8Jx16H2 ET40. Labeled 4A0 601 025E
* V8Q stock forged BBS wheels, 8Jx16H2 ET35. Labeled 441 602 025K, BBS RG043
* 2000 Audi TT factory 17" wheel (5x100 bolt pattern over the TT rotor)
* 2000 Audi A6 2.7T, 16x7 ET45, no spacers required (
http://forums.audiworld.com/a4/msgs/622199.phtml)
* 2001 Audi Allroad "twin spoke" 17" (7mm clearance)
* ASA JS5, 17x7.5, ET35
* ATP S5, 16x7" ET 35
* Avant Garde Design SL, 17x8, ET 32. Labeled BBS 05 44 020
* BBS RK, 17x8" ET35. "Tons of clearance."
* Borbet Type B, 16x7.5, 35 mm offset
* Borbet Type C, 17x8.5 ET30. Nice fit, plenty of clearance.
* Borbet Type E, 17x8 ET 35 size. Fits fine, with about 3mm clearance.
* Borbet Type M, 17Jx8H2, ET 35, labeled H80735.
* Borbet Type S, 17x7.5, ET 35 (2.5mm clearance)
* Borbet Type T, 16x7.5 ET 35
* Ergon Multispoke 16x7.5, 35mm offset
* Moda Sport by BBS 16x7.5, 35mm offset (labeled "7-1/2J-16H2 ET 35"). Close on the face, but no fit problems.
* Ronal LV, 17" (installed on a 1995 S6)
* Ronal LV, 16x7.5" ET 35. 5mm clearance to rim, 3mm clearance to back side of spokes.
* Ronal R28, 16x7.5 ("S4 fitment" only!)
* Ronal R28 17x8.5
* Ronal R-38, 17x8 ("nearly and inch of clearance in all directions!")
In general, any 16" ET35 wheel should fit, and in general any 16" ET45 wheel will not.