Drain holes in trunk wheel well

Can't find any drain holes in trunk wheel well! Major leak and trunk full of water as well as bottom of back seat and floor on front passenger side

Trunk was filled with water. So we bailed it out to get a better look. Took all the carpet and tire, etc. Out of trunk. But, I can't seam to find any drainage holes.

Usually there is one you can pry up in other cars I've had. This one simply has two square "patches" that appear to be welded on although they do have tabs on the underside of the car. I tried prying one of these up. But, it resulted in chewing up the sheet metal instead.

We live in Oregon, so it may take a while to get a break in the rain long enough to find where the leak is coming from. Right now I need damage control. I just want to know if I'm going to have to drill my own hole in the base of the trunk. I'd rather not do that unless there is no other option.
Thank you to any and all suggestions!