Currently doing some research for an idea I have had.
I would like to know approximately how many MX5’s there are out there with the hard folding roof. UK figures would be good but interested in world-wide also.
I think they were first introduced around 2007/8 on some of the later MK2 models although I think they are more common on the MK3 versions.
Anyone out there know, or a good place to start?
There were no Mk2’s with a folding hard top. The Mk3/NC was made from 2005 to MY2015. The NC was the first MX-5 to offer a hard folding roof option. As to how many there are I don’t know.
In the order of 250,000 MX-5s have been produced since the NC was introduced (guess). So the number of NC hard tops will be rather less than that.
Can use this for how many 5’s left but won’t split down to PRHT’'s
https://www.howmanyleft.co.uk/?utf8=%E2%9C%93&q=MX5+ROADSTER&commit=Search
Thanks for that. Even if 5% of those were hard tops that would be over 10,000 units. I should have taken a sample at the National Rally & extrapolated the data!
Are those UK or World figures btw?
Manufactured, so world. It was a guess.
From Wikipedia-
The 250,000th MX-5 rolled out of the factory on November 9, 1992; the 500,000th, on February 8, 1999; the 750,000th, in March 2004…
On April 22, 2016, Mazda broke its Guinness World Record by producing its one millionth MX-5.[2] The one millionth car rolled off the production line and was shown in select cities, where the first 240 fans of the vehicle present could physically sign it before it went to the next destination.
So about 250,000 were made from early 2004 to early 2016. That will include some NBs and some NDs. So maybe I should amend my guess downwards a bit.
It would seem that the NC is the only mark with a full PRHT, the NA and NB didn’t and the ND RF is something totally different. So just the one mark, that should make things easier for you!
I’m intrigued by the “idea”…
Well I know there is definitely at least one 
We spoke at the National Rally. It was about the problem I had with the roof after leaving a bag in the roof storage area behind the seats & how to repair the resulting damage.
My idea is “prevention is better than a cure”.
Mazda produce reports full of production and sales figures for each model as part of their investor relations, those documents will have some numbers to start you off.