The written instructions are not that clear. For example, they want you to take the wires of the LED switch. I would not try, if I were you. But the figure is pretty clear: it shows a LED switch with detachable wires, while the switch comes with soldered-on wires. Just follow the wiring according to the figure. I put the front of the car on my Rhino ramps, as recommended on miata.net. It does help a lot.
Brackets (took 3 hours):
I installed the brackets to holds the lamps first. This took 3 hours. My tie-down hooks were already removed. I followed the instructions on miata.net. The bumper has in the top of the mouth indentations; the brackets go on the black plastic exposed by the outmost indentations. I put them as far forward as possible which puts them slightly towards the center of the car. I figure, the further forward, the less heat problems while idling at rest. Also, I wanted as little interference with my grill and intake air as possible.
The lamps come with reinforcement plates to put at the other side of the bumper, but this area is unaccessible. I ignored these plates. Without it, the brackets are on there solid. They are attached with both double-sided tape and self-tapping screws. The instructions tell you to first stick them on and then use the screws. But I was afraid that I would not stick them on straight. So I first marked hole positions with type-out, then checked for alignment by comparing directions with a long piece of wood put on a chair, screwed in the screws partly, and then took it loose and reattached with the screws in the screw holes for alignment. The screws that hold the lamps go in either way, so that is not a concern. Make sure that your grill attachment holes are accessible.
Main wire harness (two hours):
I ducted the wires going to the CATZ lights from the right engine bay through the corner hole next to the right rear headlight. Then I ducted the longer wire towards the left light; to make sure it does not go anywhere, I threaded it through the center part of the horizontal beam going behind the bumper. In the right 1" or so round hole, out the left. This makes it quite secure and keeps it out of the air stream. I pushed the ends out the rectangular holes just behind the lamps, and tie-wrapped them securely to the borders of these holes. Inside the engine bay, I tie-wrapped the wire bundle to the one below the head light so that the wires would not interfere with the head light going up and down.
I attached the relay to the arm pointing from the right headlamp assembly rear brackets toward the engine. This bracket holds my AC relays. The bolt is a good earth according to my multimeter. I took the retaining bolts loose and shoved the relay behind the AC bracket, facing outwards.
I ducted the power lead into the engine compartment fusebox through the indentation at the outmost side of the box. I cut off the useless ring (intended for connecting to a battery) and I put a U-shaped connector on the wire. This could be pushed into an empty female slot in the fuse box that has continuous power. Note that the CATZ wire already has an inline safety fuse.
White wire to the cabin (1 hour):
I ducted the white wire along the firewall over the engine and into the cabin, making sure it was secure using tie wraps and available brackets. I ducted it into the cabin through the hole that has a plastic clamp in it covered by a rubber cap. This hole is just to the left of the steering column; take the metal plate below the steering column out first. If you make a hole in the rubber you can duct the white wire into the cabin without the possibility of leaks. Actually I have so many wires going through this rubber thing that it does not close anymore, but no leaks anyway.
Installation of the LED switch (3 hours):
I made a rectangular hole the exact size of the switch in the center console between the seats. I made it at the driver's side foremost corner. First I took off the center console (5 screws: front ends, below ashtray, in arm rest compartment), then I used the provided switch holder to mark off exactly the required rectangle on the inside of the console with a marker. Then I very carefully used a hobby knife to cut deeper and deeper into the plastic from the inside of the console along the edges of the rectangle until I was through. I made sure that I did not cut too far, since the switch won't cover up any mistakes. Then I used a file to smoothen and widen the hole just enough for the switch to fit. It was a pain but it looks great!
Final connections (2 hours):
The white wire that was ducted to the cabin was ducted further to the switch and connected to its white wire. The black wire of the switch (earth) was put below one of the coppery bolts holding the shifter frame. Finally the orange wire from the switch needs to go to any wire that is life when the parking lights are on and dead when they are off. I used the same red/black wire that I used for my Lite Minder. The wire is on a bundle that passes behind the cabin fuse box on the driver's side wall below the dash. On a pre-96 car, you might be able to find a suitable fuse. Note that wiring schemes have changed, use a voltmeter or a bulb to test whether you have the right wire. Do not blow up the airbag. The orange wire was too short to reach, so I needed an additional piece of orange wire (OK, I used yellow) and an additional wire splice. Since CATZ uses a relay, this wire does not need to conduct a lot of power.
Finally, I connected the power in the engine bay fuse box, (no smoke,) started the engine, and tested that the lights are only on when both the switch and the parking lights are on.
The entire thing took a weekend, but I sleep late. Also, there was frequent rain to delay things.
Bozo can now be seen clearly by even the blindest retired person. If I turn on the switch, that is.