Leak in rear lifthatch water leaking into rear storage area. It appears to be getting in under the rubber gasket door seal

lots of ways, to leak rain (or other things)
windshield glass cracked
door seals bad or door warped
heater core, leaking engine coolant, (not water AF50% coolant)
the water in hand feels slimy, is not rain.!!
the cars most have cowl vent area in front of windshield glass.
this cowl when opened UP we see drains if the 2 or more drains Are clogged up with leaves or nests. the cowl floods like a bath tub
and overflows the HVAC fresh air vent, port, (a coffer dam it is)
and flows to the hVAC blower and to the floor., bidda bodda boom.
or super bad rusted car bodies sure do leak.
never ask the blind we can not see your car, blind
find shop tech to find it , living hands on work.

Well you didn't specify where it's showing up in the vehicle if its the trunk make sure the trunks weather strip and seal that goes around the body and seals when the trunk is closed is not broken and also the trunk has seam sealer for the body joints and welds make sure theres not even a pin hole in it ,a leak can also be coming in through the windshield fr/rr from the sealer under the glass getting brittle in the front there is a cowl screen that keeps out leaves and other debris and it has a rubber gasket on it this can dry up and break and this applies to water only if you see antifreeze it's your heater core unless your using straight water forengine cooling which you shouldn't be another leak spot is all the doors insulation rubber and the window strips if they are severely worn water can run down freely into the doors and from sloshing around inside can drain into the passed compartment from a rust door skin on the bottom

Can't fix anything till you find out where the leak is

Get inside & have someone run the hose on it

Remove whatever trim you have to,to see the water
entering

If silicon is working,I would go with it,silicone last a long time and it's working.

For water leaking inside the rear door panel, I'll suggest you check and replace the black rubber/foamy seal that is part of the high-mounted-rear light assembly.
It gets weak over time and soaks water, thereby allowing water seep into the booth lining and also into the underlay of the carpet.
If you have a cracked rear-light (the one attached to the boot hatch), you may also get a leak.
Change this rubber seal/ gasket. I used an old rubber carpet to make a gasket to fit the light assembly, and it stopped the leakage.
Hope this helps.

I had water coming into the rear storage area. Finally found where it the leak was. The plastic panel on which the license plate mounts was leaking around the panel allowing water to run down onto a little ledge area and the enter the rear storage well at the left rear corner of the storage well. I have tightened the nuts that hold the panel against the gasket and if that does not stop it, I will loosen it an put clear silicone seal around the pane. It was hard to figure out! I had to remove the rear trim to see where the leak was. Hope this might help.

We had same--water on driver side rear floor (soaked!). Driver side front floor seemed dry until feeling UNDER rug, was slightly damp. We found the location of TWO leaks causing this.

Leak #1 was through the parking brake line/cable seal; Recaulked with silicone. Removed plastic trim on floor between floor and door to reveal metal channel filled with water.

Leak #2 was where the door meets the car, near the hinge. It was the accordian-looking tube housing the wiring for the door. The big, rubber, circular plug connecting it to the main part of the car had come loose and water ran down through that, into the SAME metal channel filled with water from leak #1; will seal with silicone.

Note: We found that the channel filled extensively near the front door, BUT the carpet edge from the floor near the rear seat was dipping into it, wicking it up to the rear floor. Also, upon acceleration, the water in the channel gushed toward the back, thus soaking the rear carpet.

These leaks were found by removing all plastic trim (covering edges of carpet by doors), then one of us pouring water into specific areas of the exterior of the vehicle, and the other one watching closely with a flashlight for any signs of dripping.

It's probably coming from the sunroof drains being clogged.

Open the front door, look closely, you will see a rubber tube sticking out 1 inch. Cut off the tips so the tube is wide open.

It could be coming in through the rear door as the rubber might not be sealing properly the easiest way to find the leak is to remove your seats and carpet sit inside get someone to squirt the car round the doors and windscreen air vents.

The most common source of this kind of leak is the windshield, have a glass shop check the sealing around the glass