Below are pictures showing how our TS2 seat installs in an NA or NB Miata.

Step 1: Bolt the floor rails in place. In the picture below the factory flange bolts to the floor were replaced
with hex head grade 8 bolts.

Step 2: Bolt the base to the floor rails using (6) 5/16 x 18 x 5/8 grade 8 button head cap screws and washers. There are two sets of holes in the rails for mounting the base. One set of holes is 2" forward of the other. In the picture below the base is mounted in the rearward set of holes which allows the seat to be installed back to the wall if needed.
Step 3: Set the seat in the base to estimate the legroom position desired. Align the seat with the nearest
set of holes on each side of the base and bolt in place from the inside. Use (2) 5/16 x 18 x 3/4 button head
cap screws and washers on each side where bolting thru the back and bottom. Use (2) 5/16 x 18 x 5/8
screws and washers on each side in the more forward area where bolting thru the bottom alone.
If your seat comes upholstered you will be able to lift up the side bolster covers  to access the mounting
holes above. The covers will be held on by velcro and you will be able to pull the cover out from under the
plastic grommet around the lap belt holes. The picture below shows the shoulders did not rub in the NA
used for the demo install.