Hi all. After a mk2, mk2.5, mk3, mk1, mk2.5 (and then going to a ‘sensible’ car for a year), it’s time to return to the fold with a mk4.
I’m looking at second hand ones, 2016 onwards. Is there anything to look out for on this generation that I should pay extra attention to before buying?
Hi Peter.
My advise would be, if you are buying a 2 litre model would be to get the ND2 with the revised engine (184). The gearbox had a few internal upgrades in order to reduce failure rates (Well discussed topic here at the OC!) If you are looking at the 1.5, both ND1 and 2 are fine.
Checking the condition of the rear hub assemblies is key, they are a very costly replacement and one worth avoiding if you can.
They are generally too new to have rust issues though a number of members here have added underbody protection to their Mk4’s.
Prices are high at the moment, but just find the nicest you can and enjoy it…! 
Rob
Have a look here Technical Service Bulletins (miata.net) for a comprehensive list of ‘issues’.
Don’t get too hung up on any of them. Just be aware and check any prospective cars individually.
Sorry, what a div, forgot the link which is now showing.
Nd2 will still be in warranty too
I recently bought and it had to be ND2 for the engine & box revisions. Good luck though, the prices were a bit nuts when I was looking back in April, since then they’ve got even more nuts!!
Thanks everyone - some great things there to add to my list! When did the ND2 come out?
I think mine was quite an early one - registered in September 2018… (2019 MY)
Rob
@Peter_the_Shark , I’d do a bit of research on the hood wear issue where it rubs against the rollover hoops, some cars seem afflicted others are ok. I think there are some photos on this forum. The other thing is take a look at how many stone chips it has. The demonstrator I drove was badly affected. Also the drivers seat seems to have noticeable ‘cheek depressions” 
on some cars especially with leather. I bought a new ND in March and so far these don’t seem to have developed on mine, but the 2021 seats do have a different perforated leather facing, so maybe the internals have been beefed up.
Whilst I did buy new, (1.5 Sport Roadster in Soul red) I also came to the conclusion that an early well cared for 1.5 SE in white would be cracking value at around half the cost ! Prices may have firmed up now though.
BTW , totally agree with previous comments.
Enjoy the chase. Ownership is even better.
ND2 was model year 2019 I think. It varies by trim grades but the ND2 got various additional driver aids. Some of the ND1’s also have lane-keeping but fortunately it can be turned off. Somebody pointed out to me that the factory reversing camera that appeared on top trim ND2’s makes the rear of the car look like a cat’s bottom, and now I can’t unsee it.
I bought in Sept 17 and IMO the ND1 1.5 was better than the 2 litre (I had a decent test drive in both before buying a 1.5 which I have no intention of replacing). With the ND2 the main reason for preferring the 1.5 has been addressed, as the 2 litre engine received the attention that the 1.5 had been given for the original launch.
The SE, and I don’t think there were many, lacks the LCD screen if that matters, Nor I think do they have the LED headlamps.
I wouldn’t worry about baggy leather seats, they pretty much all did it because the seat construction resembles a deck chair - instead of the usual metal base and foam insert, the non-Recaro ND seats are just supported by webbing. They can be made to look a bit better with a hair dryer, which of course we all carry.
The ND1 may well be the best hunting ground for value if you can find a low miles weekend car and want a 1.5.
My 1,5 Arctic, registered March '17, has now done 18,500 miles and has been no bother but for a rusting driver’s window guide cover, for which there is a TSB and which was replaced without charge.
They don’t all have the hood problem. I have always opened mine from outside and made sure to leave clearance between the front edge and the hoop covers.
EDIT - some cars might have i-STOP (stop start), and from 2020? on, i-ELOOP, which charges a capacitor on the overrun to reduce the load imposed by the alternator. Mine has neither. I see that the quoted kerbweight of a new 1.5 Sport with both is 81Kg more than was quoted for my 2017. This seems a big difference and I’m very happy not to have these frankly gimmicky features.
A few things have been documented since it’s introduction in '15, namely
The soft top. When it’s in the down position, look at where the front edge is with respect to the back of the roll hoops The edge shouldn’t be touching it. If it is, walk away. And if it is you’ll probably find it’s frayed there, too. Giving a hat tip to da man CountryBoy, I followed his approach from day one (yes CountryBoy, years before I posted I followed your advice 
) and have lowered (and raised it) standing outside of the car with the doors opened and pushing back gently on the glass as its lowered. Whether this is why mine has a good 1/2 inch of clearance, still, maybe due to da man CountryBoy’s method.
Also, when the hood is closed (i.e up), look at the soft top in the region a bit above the windows. You might see some wear marks there. Caused by the soft top rubbing against itself when driven top down. Also, again when the top is up, look under the rear window, to its sides. You might see a line each side. Again caused by the hood rubbing against itself. There was TSB concerning the rub marks. This shows the possible effected areas. https://www.miata.net/garage/tsb/Rubbing%20Contact%20Marks%20on%20CONVERTIBLE%20TOP%20Top%20Fabric.pdf I guess weather the example you look at has them or not probably depends on how much it was driven top down.
The gearbox, primarily on 2L versions. Version 1 had the most failures. Swot up on it on the US MX5 ND Miata forum. Version 2 on ('67 plate onwards i think, but don’t take that as read), failures have been less. Again if you swot up on the US forum, maybe google something like asking how you identify which version of the transmission you got, you can decipher the transmission code easily (and hence know what version the car you’re looking at has got) just by popping your head in the engine bay if you know where to look. There’s a post on the aforementioned forum which tell you how. The Official -Facts Only- ND Transmission Failure Thread - Page 4 - MX-5 Miata Forum . I guess Mazda are the only ones who really know the extent of the failures.
The rear hub carrier bushes (or bush).
If you research this it’s supposed to present itself via a knocking sound over bumps etc. Supposed to be a brutal £700 each side, but folk have had some success with Mazda getting some help with this payment. I presume depending how long post warranty the car is and whether the car has still been dealer serviced. Consider one point though, if you have the misfortune to have the hub carrier bushings issue, the ‘replacement’ carriers are the same ones/same design as the ones which went plop. There isn’t, to the best of my knowledge, a ‘version 2’ of the hub carriers. So it’s replacing one possibly hub carrier with inherent issues, with the same design thing, only new.
EDIT; Poster DC04R correctly points out that some poly bushes have (recently) become available, so an alternative solution may be possible ref the hub carriers. MX5 parts sell them.
you can now buy the bushes instead though (albeit polyurethane so a bit firmer) so it’s not the only remedy to buy the complete hub assembly. Lot cheaper
Thing is, on mx5 parts there are shed loads of these: MX5 Suspension Components & Kits for Mk4 2015> | MX5parts - Page 2
Do you now which ones would replace the problematic ones?
I understand these are the ones. Polybush Rear Hub Upper & Lower Lateral Arm Bushes, MX5 Mk4 & RF (mx5parts.co.uk)
Thanks everyone for all the advice - I’m made a new notes. The car I was looking at got sold before I’d finished my research, so my search continues. Thanks again!