I have just ordered a set of Elise / VX220 seat runners from “randamonia” on MX5 NUTZ and fitted them. The quality and strength of the mounts is first class and the attention to detail excellent. Great instructions make these easy to install. I would wholeheartedly recommend “randamonia”’s seat mounts to you for fitting these seats to your MX5. Best £100 I’ve spent. I should point out they come unpainted, but they are very easy to paint; I used a £4.00 can of black spray paint from my local harware shop to good effect.
Here is a quick photo diary of my installation. Uses existing seat runner mounting points. Rear holes need slightly enlarging with a 8mm drill. All fittings included.
Runners slid forward to fit the front Z mount:
Slid fully back to fit bolts for the rear mounts (requires enlargely a little with a 8mm drill): 
Rear mounts fitted loosely:
Seat offered up and loosely bolted to the Z mount:
Seat bolted to the rear mounts. Nuts initially tightened by hand to minimise chances of cross threading.
General photos: 
Just bought some elise 111S seats for my mk1 and brackets off this guy. Looking forward to getting em in. Thanks for the write up
