All MX-5's (NA, NB, NC and now ND after extensive testing!) were shipped with rubber door bushing/door stops, these have tedency to wear over time and add to rattles, not only this but the bushing also assists the chassis rigidity.
We decided to design and create our own bushing to stop the usual issues drivers report with the OEM factory bush.
Installing these bushes to your MX-5 is very simple. All you need is a 10mm socket or Cross head screwdriver of decent size. Simply remove the existing bush, insert the bolts into the new bush (the tolerance is tight so bolts may need screwing into the holes) place the bush in the around about location the existing was removed.
Dont tighten the bolts too much, check the door closes correctly then tighten, it is literally as simple as that.
Light sanding may be required.
Once fitted you should notice the door closes with are more "Solid" noise and the car feels generally stiffer when driving....and no door rattles.