OEM wheels are REALLY narrow, 7.5" in the case of the MonzaII and I Beleive 7" on the polo.
We can't get a quart out of a pint pot so some spacing is always going to be required.
Andy if we know a 3mm spacer will work why not go for some 8mm hub centric spacers and remove the bolt.
I have only ever heard of one BBK that fits the OEM wheel without spacers and that was my Pro5000+ AP kit I did about 18 months ago that's on a very skinny specialist caliper that was originally fitted to a Metro 6R4
So the only car on the Mk5 platform that gets 4 pots is the TTRS which gets 8.5" wheels and spokes that are designed to be roomy, the TTRS caliper is also skinny ......same family of calipers as the ford GT
The other variable is Tyres, some are really rounded on the shoulder and some are very square.
