I have seen this a lot laterly on the TFSi engines. I usually try and replicate the fault on the dyno, often its a missfire on coilpack number 4. Only ever see it on mapped cars as well.
I usually replace all 4 plugs, if that doesnt solve it I will change coilpack 2 for number 4 and retest, if the missfire moves to cyl2 then I know its the coil.
If you need a set of coils I have 12 brand new in boxes, original VW items as well. will sell at -20% off retail.