[VrooM3]

For a few days, the car would at times not unlock the door, and when i would do it manually with the key in the door, it would not have power locks etc, not turn anything on when i put the key in the ignition.

I was reading elsewhere that it may be the receiver for the FOB, wanted some insight from you guys before i ordered the part. Upon inspection, i noticed the battery area had flooded and submerged the battery halfway in water. I uninstalled the battery, drained the water and cleaned any rust buildup, the power lead to the starter had rusted and i cleaned and reinstalled it. I then checked all the fuses on top of the battery and all had continuity.

Anything else i should check or is it most likely the IBS or is it the CAS?

I let the battery charge while it was out and it held a full 13.5V, i then checked continuity from the engine bay power leads (where you connect a trickle charger) and there was consistent voltage across to the battery without any drop.