Recently decided to order some wheel spacers, 5mm to be exact. Nothing crazy but they came up for cheap so I took the opportunity. They are made specifically for the MX-5 and are hub-centric too, sit perfectly flush against the hub with no play at all.
Just some photos of the spacer and how the car now sits.
Visited MX-5 Plus today, like nearly every weekend, and picked up some offset number plate brackets. The standard number plate bracket is flimsy and often bashes against the front bumper, leaving behind scars/scratches. The MX-5 Plus bracket is thick as well as placing the number plate to the side, definitely over-engineered.