I have noticed the rear tail lights hold water after a rain or car wash...the only way to get them to drain is raise the hatch....i don't want this to become an internal rust problem down the road.....anyone else?
If I'm understanding correctly, the water is pooling above (not inside) the tail light. Is that correct? If so, is the water pooling against plastic or a painted surface?
One thing you can do to help prevent pooling against a painted surface is to wax/seal around the painted edge of the hatch opening. The same property that causes water to bead and slide off the hood, roof, etc. (hydrophobia) works there too. So even though you don't get to enjoy the shine that comes from waxing all the outer panels, having the water glide off of the channel along the opening should help prevent pooling.
If the water is just pooling in a plastic area, I wouldn't worry too much about any harm coming from it.
I gave it a try. This is about 2.5-3 hours after a heavy rain. The tail light area, black plastic thing, and channel around the hatch opening were all completely dry until the hatch fully opened, at which point some water ran down off the outside of the hatch/glass and then down the channel and on to the black plastic thing as shown. I didn't see anything coming from the tail light itself. And again, it was completely dry before I opened the hatch. If there was water there before, it must have run off somewhere in the 3 hours before I checked it out. For reference, mine is a 2019, and I believe an early build.
When you say the tail lights hold water, are you seeing it run out from the top edge of the light and down along the hatch when you raise the hatch?
The gap between your rear window and the hatch itself holds water and rarely goes away unless you open the hatch or like the crazy guy I am when I wash the car or wipe it down after rain I pass a small rag to absorb the water standing in there.