OK I bought ford escort track rod ends for my steering and they never seemed to sit snug. I ignored this issue for over a year as the car wasn't moving around much and though once tightened they would be fine. I was wrong. They also seemed to be pinching over squashing the joint boot due to the angle of the mx5 steering arm. People have used mx5 track rod ends (TRE) and I think Nathan has done something with another trackrod end fitted from the top rather than the bottom. But after some measuring I realised the taper was correct for the escort TRE it was just that the hole was too deep making the hole too big at the bottom. The depth of the hole was 20mm, the length of the taper on the escort TRE was around 14-15mm. So I set about modifying the track rod end masking exactly the area that needed removing and giving it a light dust of spray paint so it was very obvious.
This has worked extremely well and you can see from the image that Mazda seemed to have left more casting than is necessary for some reason. If anyone is reading this and thinks I'm an expert I certainly am not. I'm taking a calculated risk if you think this solution may be for you then be aware you're doing it at your own risk. There are probably better solutions but I'm happy and confident with this one. I've yet to do the other side, I'll take more pictures to show better detail.