After doing lots of research after having purchased the car before pickup, one of the things I wanted to do pretty much straight away was add DAB, Bluetooth, Carplay and so-forth. The car came with the 6-disc MP3 changer head unit - and it has 6 speakers (is that standard?). Here’s the results of what I did, the decisions I made and why I made them and the stuff I did it with (with links).
The parts I used were;
Pioneer SPH-DA130DAB Double DIN Head Unit (Purchased from Halfords - the 10% discount comes in useful!)
Autoleads DAB-AA1 Windscreen Mount Active DAB Antenna (Purchased from Halfords)
Dynamic Sounds Mazda MX-5 Double DIN Fascia Fitting Kit (FKIT-MAZDA-07) which has;
Fascia Surround Panel
Connects2 DIN Audio Interface
Connects2 Steering Wheel Interface
IL Motorsport Centre Console Storage Tray with 12V Power Outlet from MX5Parts.co.uk
Lokeke USB3 Male to Female Extension Socket Flush Mount from Amazon
After watching LOTS of videos of how to get the car apart and where the clips are, and getting a rough understanding of what I needed to do, in all this took me approximately an hour and a half to fit from start to finish.
Tools I used were;
A plastic spudger (to lift the panels without damaging the plastic)
A 10mm Torx driver
A normal philips screwdriver
A narrow flathead screwdriver
(Theoretically I also needed a 10mm socket with a long extension, but I’ll come to why ‘theoretically’)
A couple of prep steps I did;
First off, I fitted the USB interface to the centre console storage tray instead of the 12V socket it came with - the hole is pre drilled, and the 12V socket comes in a kit so I just have that as a spare (may fit it in the boot one day). The USB interface is pre-terminated which is great - the only thing I had to do was widen the hole in the tray very gently using a round file to take off less than half a mm. The USB interface then slid into place nice and solidly and I fixed it in place with the locking nut. If you want the boot, don’t forget to fit that first 
Then I fitted the Head Unit into the Fascia kit - in the case of the pioneer you have to take it out of the metal slider case using the keys provided, and then you fit the plastic tabs in the fascia kit that mate to the slots round the edge of the double DIN ‘hole’ in the fascia. You slide the radio into it’s place and use the screws provided with the stereo to fix it to the plastic tabs which are pre-drilled. Once that’s done, final step with that is to fit the bezel round the edge of the stereo (the one that came with the kit - not the one that came with the head unit, as the kit one has a curve to match the fascia).
Finally you can link the Pioneer DIN cable to the Connects2 DIN audio interface, but don’t connect it to the head unit yet.
So - at the car, I disconnected the battery, just to be safe.
Step 1 was to fit the DAB antenna - so I dropped the roof and removed the passenger side striker plate for the roof using the 10mm torx driver. This allowed me to coax off the pillar plastic internally (there are loads of videos on how to do this on Youtube) - and I fitted the DAB antenna top left of the windscreen. I then removed the glovebox (take the little retractable wire out of the catch on the left hand side and the glovebox comes off easily) and fed the connector across. For the moment I just used some insulating tape to secure the cable down the same route as the existing cables and then taped it to some cables at the back of the glovebox before replacing the plastic on the pillar and replacing the striker plate.
Then it was onto replacing the centre console - removed the handbrake cover by gently lifting the clips at the edge of the leather and pulling the whole cover off, removed the gearknob. I then removed the coin tray to expose the screws, the front cup holder base where there was another screw, and then gently removed the plastic cover right at the back which lifted up and forward, exposing the other screws.
I took out the screws around centre console and lifted it gently over the gearlever - you need to disconnect the electric window cable which will restrict how car you can lift it - again there are lots of videos on youtube - once you can feel where the clip is, you just gently push in and it pops out fairly easily. There’s also an instruction leaflet with the storage tray that shows you how to do this.
I removed the felt stuck under the cupholders, and then unscrewed the cupholder tray. The new tray fits in place but you will have some screws left over as it has 2 fewer screws than the cupholder tray - so I screwed them back into the posts even though they weren’t holding anything in. I pushed the felt back onto the bottom of the new tray, and tacked the USB lead with insulating tape to the underside of the tunnel away from the gearstick so it doesn’t obstruct anything. I then re-fitted the centre console, ensuring the USB cable was pushed under the aircon controls where I could grab it easily in a bit. Again you’ll have 1 screw left over as the one in the cupholder isn’t there any more. Refit the plastic cowling at the back of the console, but leave the coin tray out for the moment.
So now it was onto removing the radio - I removed the two plastic wedges either side (again - many videos on Youtube showing how to do this - effectively there is a tiny slot at the top which you can lever under and they just pop off.
There is then two screws - one on either side - holding the radio in.
Now - if you’ve got a newer MX5 than I do (so a mk3.5 or newer) - you may have to keep the centre console off as the radio is bolted to the centre console - mine isn’t so thankfully I could put mine back.
Also, some Mk3’s seem to have a 10mm bolt at the rear side of the radio which you have to remove the plastic under the wheel and the metal plate - I wonder if that was the US version only because mine had the plastic, no metal brace, and no bolt. Phew.
Anyway - at this point holding either side of the radio module it should just slide out. There are some clips either side which locate into the dashboard from the existing fascia and once they’ve unclipped it comes away easily - but be gentle here. In my car, the cables were quite short, especially the antenna. There was 3 cables I had to disconnect - all use the same clip method of squeeze the clip in the middle and pull - there’s a connector on the aircon controls, one on the back of the radio at the right hand side, and the antenna on the left, which is covered in foam.
Once you have them all out them the radio is out. You now have some transplanting to do;
You need the metal clips that are sat over the plastic clips that come up the side of the fascia and transplant them to the same plastic clips on the new fascia.
You also need to unscrew the aircon controls and transplant the unit over to the new fascia.
Now you’re nearly ready for re-assembly - but the last thing before that is to put in the microphone for the bluetooth/phone and voice control. I located mine in the instrument cluster on the top at the back of the steering wheel cowling. I then fed the cable in through the side - because you have the radio out it’s easy to feed it through and pull out where the stereo gap is. You also want to locate the DAB antenna connector at this point too. I had quite a bit of slack on both so I coiled up the majority and then tidied it with insulating tape.
So - assembly. I plugged the DIN adaptor cable (with the affixed remote control module) into the cable that was plugged into the back of the Mazda head unit. I then plugged the Pioneer Cable into the DIN cable - and you now have a choice - you can either link the green wire from the pioneer cable to the handbrake cable, or do what I did and I stripped a bit of the green pioneer handbrake cable and wrapped it round the metal earth strut just to the right of the gap where the head unit fits - and used insulating tape to keep it in place. This links it to earth which solves the problem.
Connect the Pioneer cable to the head unit, find the USB cable, and I suggest may be easier to use the cable extension provided in between the armrest socket and the back of the Head Unit, as the extension’s USB plug is slim - although I had plenty of cable to reach the back of the head unit from the armrest socket directly, the plug on the end of it was too long and wouldn’t allow the head unit to slide back properly.
You also need to ensure you try and locate as much stuff behind the aircon controls or either side, rather than in the space for the head unit as there’s very little room behind the head unit once in.
I linked up the FM aerial, DAB aerial, 3.5mm jack for the steering wheel remote module and the 2.5mm jack for the microphone.
Once I was nearly ready to push back in I also re-connected the aircon controls and then pushed back in. Assuming you’ve made sure the cables are neatly out of the path of the head unit it should slide back in and the metal clips will locate either side.
You then replace the screws either side of the fascia, replace the plastic triangles either side, replace the coin tray, re-assemble the glove box and then re-connect the battery.
So - here’s the show and tell for me - this is what mine now looks like;
If you look just above the steering wheel you should be able to see the mic just at the bottom right of the rev counter - and it works perfectly there. And it’s so nice that the steering wheel controls all work perfectly.
Here’s the USB socket in the armrest - with my lightning cable disconnected to show you where the socket is.
This is what it looks like when on and all squared away.
Because it has Carplay/Android Auto you have full maps and navigaiton as long as your phone is connected - but it also does the Pioneer AppRadio+ which supports Waze too.
Plenty of space for an iPhone 7 in there (or a 7 Plus or X - and also have tried Android Auto with my work Galaxy S8 and that works fine too).
Finally, DAB - this works way better than I expected - in fact with the screen antenna, it’s even better than my Skoda’s DAB - on the M62 in certain locations, and in the centre of York, I get the odd place where DAB cuts out in my Skoda. The MX5 so far has been rock solid so I’m impressed.
Sorry this is a long post - I hope this helps someone!
Mark.