Just a final post from me on the issue.
Have now decided to take a (significant) hit on depreciation, and bought a year old petrol Grand Scenic.
Its a world apart from the Zafira, driving exactly as it should. Strangely, Renault's claimed average mpg is worse than that of the Zafira - although the Scenic is currently averaging 37 as opposed to the Zafiras average 28 mpg...
All this does is reinforce there is / was a problem with the Zafira, and other posts in this forum serve only to reinforce this.
Life's too short to have to worry about a car being reliable, and buying brand new "should" have given a certain amount of certainty to this.
Vauxhalls idea of customer service is a joke - caveat emptor....