Here's the thread about the water leak and what to do. The scr is difficult, hopefully BMW helps you there.

Injector, you may need to replace it. I used a multimeter to diagnose which ones were shorted- they should be at least 500k Ohm to ground.
Here's the thread about injectors: https://xoutpost.com/bmw-sav-forums/...gine-dies.html

Here's the thread on the plastic partitions breaking and shows the issue with the foam soaking up water etc.

Error code 4B99 and 483D - Bimmerfest - BMW Forums