Did you use license plate camera or drill a hole by license plate lights and install an OEM look camera? Looked like license plate camera would block trunk release. My mirror can control a second video output, so I may mount it up front. How did you route wires?
Even oem cameras get the water blockage sometimes. Seen people either use RainX on lens or make a small shield above camera to shield it from moisture...
I used this:
It replaces one of the license plate light casing. Put the oem light bulb inside and the camera is attached to the casing.
No drilling required.
Wires to the fuse box were run down the A pillar. Video cable was run along the ceiling to the back, through the lift gate rubber hoses (PITA, I ended up cutting the plug and rejoining the plug after feeding the wires through. I pulled off the plastic trim panels in the hatch door, and took off that plastic piece that's above the plate (the piece that holds the 2 plate lights).
I'm not sure how detailed you need me to get or how much experience you have in this stuff so I'll stop for now. lol
Before I started, I wanted to write a guide but I didn't know if there was really a demand for this (since I'm sure more people are interested in getting a back up camera to work on their infotainment instead) and I also never installed something like this before, so I didn't bother in case I didn't do it right. But in the end, looks like I got it to work fine.
Let me know if you have any more questions.
I'm planning to cut a small piece of plastic and 3M-ing it to make a shield since the camera can't see anything once rain drops are on it.