there’s a website (at least one, definitely more) where there are detailed technical diagrams of the mx5, basically every little part of the mx5, down to the last bolt.
it gives serial numbers of the parts etc. i’ve used it a lot in the past but i can’t find the links. the diagrams look like this:
thanks! 
thats a very good one. i don’t think they have the one part i’m looking for but they certainly have loads of great info.
I don’t think the Mellens site shows part numbers. There was or are a number of USA Dealer sites which have the part number information but the one I used has been withdrawn and they only had LHD information anyway…
Miata.net has had for decades scans of microfiches for NA and NB, plus collision repair sets.
https://www.miata.net/garage/90-99Parts/index.html
Arrive in Japan has equivalent for Japanese RHD.
http://www.do-da.co.jp/sun-mec/partslist.html
Its a bit better, as not only the scanned image, but they have extracted into html the part number, description, even the yen price (use a translation programme).
The scans are not great for part numbers, as there are two different sets of part numbers. Some part numbers are assemblies, rather than individual parts.
In any case, in general, you can’t really walk into a Mazda dealer and ask them to order based off a part number. They need a VIN. If you have a JDM VIN, unless the dealer has paid extra for the global EPC (ie. why should they?), computer will say No. So its always handy to have a UK VIN equivalent to your car’s age.
If you order off a JDM VIN, there is a no return policy.
I was looking for this one too last night, silly me had it bookmarked in my favourites. It’s mainly for the NC though.
https://www.mellens.net/mazda/Mazda-Miata-2008-2009/index.html
Having looked again it’s just an extension of that first one I posted if you scroll to the foot of that page.