As said no you dont need any spacers - you only need spacers if the 256mm rear brakes came from TT / 4WD MK4.
cheers for all the reply you lot, very helpfull, why isit the 4wd carriers are different ? are they spaced different because they run different hubs or something ?
don't forget to either change your splash guards or grind the lips off the ones you have now
Yes mate, just finishing stripping down the calipers for a lick of paint then i'll book some time in DH & Mikes man shed to pull the rear beam off