The NA and NB Miata/MX-5 was never delivered with a roll bar or other protections above the headrests.
The 94- and up got an extra bar behind the headrests to improve side impact protection but it hardly helps if one should get upside down.
The same goes for the numerous stylebars out there that looks ok but gives little protection as most of them are attached to the seatbelttowers.
Actually they could make a roll even more dangerous as they might collapse in the drivers direction and do some interesting stuff to your head.
I opted for the Hard Dog Hard Core M2 as it is legal for racing in the SCCA Solo 1 class in the US and might be legal for the Roadsport class here in Norway.
Anyway its nice to have something designed for protection on the track rather than just something made to look good.
The Hard Core M2 bar don't have a harness bar and works with both the NB and Cabrioworld glas rear window zipperless tops mounted to a NA.
Another good thing about this bar is that there is no welding required. Me and my mad welding skillz in the proximity of the fuel tank ---> itsgonnablow
Installation was straight forward. I wish I had some help the first time i lifted the bar into the car as I later discovered that the ABS wires going to the rear wheels might have been damaged in the process.
The installation required some cutting in the package shelf, fuel tank cover and the side plastic panels.
I used a sheet metal cutter for the job as can be seen by the finished result

I don't care if it looks ghetto as this part of the car will be covered by carpets anyway.
I guess the US spec Miata has the ABS wires located in a different place as one of the bolts for the rear mountings fitted exactly in the hole for the grommet.
I didn't notice this before I started to drill the hole from the top side and I might have damaged some of the wires in the process as the ABS light is on constantly.

To get the holes in the back to align perfectly on both sides I had to use the OEM car jack to push the bar out from the fueltank. I'm soo smart....

The back-up plates and bolts from underneath the car.

I later sprayed these with 3 layers of Tectyl to prevent corrosion.