Just this week, I installed into another MX5 NC automatic, a 4.4 final drive with an OEM lsd..
Its one of my favourite modification on automatics. Especially enjoyable for owners who use the manual gear selection alot on their automatic mx5 nc.
The mx5 NC comes already with an automatic gearbox befitting sports cars. despite being a torque converter gearbox, it changes up and down gears crispy and cleanly. Quite intuitive too and in manual mode, its one of the few automatics, that allow the owner to actually hit the rev limiter without changing up a gear by itself.