Agree, it looks like something is causing the brake lights on the left side to stay on. Faulty ground or corrosion in the trunk wire harness connectors.The left side almost looks like the brake lights are on. Maybe bulbs were forced into the socket wrong? Are all the bulbs the same? How do the lights look when the brakes are on?
Or could be a bad ground connection on the right side.
Agree- for some reason Honda did not use the weatherproof connectors here. Puzzling since the trunk can get so swampy when the tail light seals fail.This is common, there are threads on here that discuss how the right rear tail light harness is actually the "caboose" for the cars electrical system, hence the lower volts. Once you see it you can't unsee it and now when you peruse NSX galleries you'll notice it a lot . Those that have converted to LED no longer seem to have that issue but it introduces other things you'll need to address (brake warning light indicator, LED load equalizers, modifying relays, etc.).
The caboose on the train metaphor seems to imply that the right side is tacked on to the end of something. Not an exact metaphor; but, not completely in error either The right side and left side tail lights are on completely separate circuits, fuse 39 for the left side and fuse 38 for the right side. When you look at the diagrams in the ETS, the left side tail lights are the only thing on fuse #39. When you look at fuse #38, there is a pile of other stuff connected to the fuse #39 circuit. However, most of that other stuff consists primarily of the little light bulbs that illuminate things like the switches. The big extras would be the front parking lights, the rear side marker lights and the license plate lights. In addition to these extra loads, the right side tail light circuit has more connectors in the circuit before it finally makes it to the light bulbs in the tail light.This is common, there are threads on here that discuss how the right rear tail light harness is actually the "caboose" for the cars electrical system, hence the lower volts. Once you see it you can't unsee it and now when you peruse NSX galleries you'll notice it a lot . Those that have converted to LED no longer seem to have that issue but it introduces other things you'll need to address (brake warning light indicator, LED load equalizers, modifying relays, etc.).