Moss Miata’s Interior Lights Kit -159-950 is well put together, it’s almost plug-and-play. Most NA Miatas are lacking in interior lights, so this does a great job of improving the interior while looking completely factory.
The wires are pre-cut to the right lengths, and the lights fit perfectly into the footwell trim using existing cutouts. The kit even comes with incandescent bulbs that match the OEM ones.
For the ground wire, this kit has a ring connector that attaches to the screw in the factory light switch. There is an included T-Tap Splice for 12V power, which I generally don’t like. I soldered the wire into the existing 12V instead. T-Tap splices don’t make a reliable connection since they try cut through the wire insulation, and the cut they make usually damages the metal wire inside.
I found the easiest way to install was to take out the glovebox (two screws on the bottom hinges) and gently pop the passenger interior light out from behind.
I think they turned out great, but I ended up retrofitting an overhead dome light too.