I may now know why I have been suffering from headaches recently.......

thanks for the replies - re the sensor i think its the one in the head, but will check. As for trying it myself it looks pretty straight forward so I'm up for having a bash at it - only problem is the need to clear the faults with vagcom - I don't have it myself.

May consider just replacing the plugs anyway - if I still have the problem then its must be the coils but to check I can swap them as suggested and if it misfires then it would confirm and I can just replace? I know changing all the plugs is unnecessary but its got to be better than paying the dealer to do what seems like an easy job?