Guys, Finally had the time to take out the non-working camera and install the new one. Just sharing some things I've found out from the uninstall / re-install process:

My old busted camera due to water entering through these holes/spaces at the back:


My old busted camera showing condensation on the lens. Aha! That's why there was fog on the display!


So, what I did this time was use my glue gun and fire away! I sealed the whole back part by letting it swim in glue gun glue. I will still apply black silicone sealant to seal the space between the tailgate and the plate number light trim to prevent water from sitting / sipping on/in the space.

I will return the broken camera and ask for a replacement. They said it was water proof right?