OK, have finally sorted my overhead storage box problem from dropping every time I drive. I realise that my Cali is 10 years old this coming week, so things are expected to wear out. What I have done is raise the electric roof, to gain access to the catch and two screws that are fixed inside the storage box roof,unscrew both screws enough to allow a packing piece in to the gap. Nip up the screws and what you are doing is dropping the catch two - three millimetres ( with the packer in place) allowing the latch to fully locate enough to stop any free play. I can now fully use the storage box over most road surfaces.