My car was made just before yours Tim, and registered on 1st June 2013, so I am watching your thread with great interest. So far mine is quiet, but I have no reason to suppose it will remain so.
Did I recall that the cost for the improved Centa unit was £700 fitted? I believe that this is close to cost price, however, I agree with you that the original component is not fit for the purpose, so why should we accept a substandard piece when a better one is available?
I know many people have gone down the route of paying for the latest one, possibly in exasperation at not having a working car, and whilst I would not want to take advantage of Morgan, equally, I would not want them to take advantage of me, or any other customers' goodwill.
I think the point resolves around current consumer law in the UK, something which I know very little about, but are there any 'experts' here who can clarify the situation?
