its a common problem with these cars
usually happens when people have their windows tinted
the water drips down to the left side of the trunk... where a bunch of electronics are located.
check there for dampness
'03 745i - modded - GONE -
'09 HONDA CBR600RR - GONE -
'08 535i - Sport - Sport Trans - JB4 - Catless DPs - Intake -
'07 SUZUKI GSXR-750 - Gray/Black - Akrapovic Titanium Exhaust -