BMW E65 boot and rear floor water leak
750Li
Where does the water in the E65/E66 boot come from?
One cause is a blocked sunroof drain hose. The hoses run behind the front wheel arches, and cleaning them can fix the leak. The sealing compound in the tailgate seal groove can also dry out, letting water into the boot.
Why is the E65's rear floor wet?
A common cause is the vapour barrier plastic behind the door card having come loose, letting water in through the door. Water can also come from the front if the car is parked nose up and the water runs down to the B-pillar.