The air con on my fiesta has never been good, and is crap on all these models, evn tried it in a fiesta st and its rubbish.
Been regassed 3 times in past week, so done a bit of diggin around on various forums, and was told that if i insulate the cold air con pipe it gets much better, I thought yea right that aint going to work.
When fords regassed it, the lowest they could get it was 18dc
When quick fit did it, they got 7dc
When SK autos did it, they could not beat 7dc
I did some insulating of pipes, wrapped in foil then foam. see pics
Not the prettiest, but it works, my temp is now down to between 3 and 4dc