Bring More WATER!! (No Crank-No Comm after Rainstorm)

As my good friend Keith DeFazio says, Euro cars are FISHBOWLS! This 2007 BMW Wagon had some significant water intrusion in the trunk area, and now refuses to crank over with several modules being OFFLINE. Where would you start your diagnostic process? This is a fun one, let s go! THINKTOOL PROS: https://www.amazon.com/dp/B08SWH2KP4?ref=exp_pinehollowautodiagnostics_dp_vv_d ON SALE NOW FOR $975................GET ONE!!!!!! Ivan