Sealed it as best as I could using black silicone caulking in the bottom corners. It’s not possible to completely seal the crack as it is required to allow the bottom seal to flex to meet the window as it slides. I also resealed the plastic liner with a generous helping of caulking. It still leaks, but at least the leaking water is now directed out the holes in the bottom of the door, rather than out onto my carpet.
Is this the way doors are suppose to work? Or do I have more sealing to do?