2002 Toyota Tacoma Double Cab water on rear passenger floor

I have 2002 Toyota Tacoma Double Cab. Whenever we get heavy rain, I’ve noticed the floor in the rear passenger area is wet. The water doesn’t appear to be coming in from the windows, rear slider, or door seals. Once the floor is dried out, I’ve tried replicating the issue by spraying water on the truck but the floor doesn’t get wet when I do that. Anyone have that issue? Anywhere else I should check? Thanks.