Super ideas on this thread.
I wasn't happy with my temporary solution (battery powered tap lights), and I went with the Diode Dynamics LED strip that @ThisOneTimeSubaru7x posted above pn DD0192-74 (I got warm white 3000K). Followed his install tips, great stuff.
Nice enough kit. Wires are surprisingly thin to me, but the LEDs are drawing very little amps and the wires don't get warm at all so they are appropriately sized. I opted for a somewhat stealthier install, just in case the sticky strip leaves some weathering mark after a 3 year lease. Poked the wiring forward under the headliner into the ceiling recess that holds the third row center shoulder belt, and wrapped the LED strip around the inside edge. Plenty of light, and with LEDs all around, there are no weird shadows. Depending on how hot the strip gets, I might stick a layer of translucent scotch tape on top of the plastic to add some softness to the light.
One mod I made was to solder a bulb socket to the kit's bulb socket take-off adapter (in parallel), so I could keep a lit bulb inside the side light socket. That side light doesn't do much by itself, but I found that I was missing the extra light source when I hooked up the LED. Might also be that my off-center placement in the seat belt recess benefits from the lefty light source. Anyway, the switch now toggles both the side light and top LED strip together. I lined the back of the side light recess with foil, and added insulating tape over the side light's metal contacts so they don't short out on the foil.
Last thing, I replaced the rear most reading lights (the ones between 2nd/3rd rows) with 194 LEDs, pn DD0027P (warm white 3000K, HP5 92 lumens). They are a noticeably brighter than stock bulbs, but not blinding or maxed out, and could probably be turned on at night by the kids and only marginally bother my driving. They help illuminate the back when seats are flipped down, but note that they are on a timer unless you keep a door open.
F.S.
