Well its fixed (sort of!) for now (fingers crossed)

But yes, its disappointing that having agreed the symptoms were there and were not typical for the car then they should have followed it through. The trouble is what do they change first, if there is nothing in the diagnostics ?

Either way it wouldn;t have been too much trouble for them to email Porsche Germany Technical for advice.

I still think you should write to cstomer Services at Reading HQ and copy to your local OPCs, detailing each visit, symptoms and reaction at the OPCs. Its a sad fact that with these types of issues you have to push to get any progress.