Wet rear driver floor after the rain

I'm now having a lot of water intrusion somewhere, soaking the rear passenger side floor pan, plus some in the pan under the front passenger seat. Spouse called out some water drops on front passenger mat, possible drips from the AC/defroster or even just opening the door during heavy rain, but that front floor pan remained dry. Headliner and seats were all dry. The whole interior has since been dried.

The rubber trim around the sunroof has been deteriorating for years, and I removed most of it a few years ago, without any leak problems before now. Significant tree debris had built up beneath the mechanicals, I've now removed most of it.

The windshield was replaced this summer. I can easily push a monofilament line from sunroof area down along the A pillar outside the glass seal on the driver side, so this seems like a drain path. The passenger side is mostly obstructed, though I finally did find a path that this 0.065" line can barely thread in to. I don't now if it was open before debris removal, or if it may have been blocked by sealing material with the new glass installation. But these possible drains seem too low to account for any possible backup to the rear area.

At the rear corners of the solar module, I did find possible drain paths beneath trim leading to the rear hatch, and cleaned them. There isn't any tree debris around the hatch seals or struts for any water dam backup. After such a problem on a prior car, I've since kept this area fairly clean. Spare tire well is dry.

I don't see anything obvious around the door seals.

Are there any other ideas for things to be inspected or cleaned before exposing the car to more rain or a carwash test?

A previous car had drain nipples at the front corners of a sunroof pan, feeding drain tubes down the A pillars. Age had shrunk the plastic tubes enough to pull off the nipples, causing obvious headliner wetness and discoloration. (Fixed by re-stretching tubes and adding hose clamps.) I don't know if this car might have a similar drain system, but it has no similar headliner damage, at least yet.