Thanks Mike - I had an interesting conversation with warranty direct on Saturday. - I explained to the engineer the dealership cost of £178.00 for more investigation.
He was pretty miffed with them charging that! Basically he told me that the dealer has quoted them £302.00 to replace the condenser inc all fitting, and that the £178.00 is half the job done - so asked me to call them to confirm with them that if it's 'my' fault (stones etc) - that the £178.00 is
not charged on top of the £302.00.
He also suggested I try a different garage as well hmmz I have so little time off work I'm not sure the best thing to do.
ps. Mike have you replaced yours then? If so do you want to do mine?!

I'll happily give moola to you mate than the dealers!