I can only concur the experiences with Mazda warranty; pretty awful. I was seriously tempted to get rid of my MX-5 for a Fiat Spider because of their poor responses.
Well I have done just over 80 miles with the new hood fitted. (due to a stay in hospital) and today the inner lining has fallen down again. Tomorrow I shall be back to the dealers with the part numbers and try to get a permanent fix. As much as I love the car if they can not fix it then I shall sell her and get some thing else.