Thanks Gents,
I have downloaded the Owner's Manual now and I am reassured that I have not lost the plot just yet. I will have a go at the Lexus service site when I can afford it and print off some of the info before they log me out. Many thanks to all of you who kept me sane,,,,,watch this space.
Meanwhile I have fitted the bars, Atera Signo RTD £150 from the Roofbox Company (made in Germany) and a homemade perspex cover for the pan roof switch, I just hope my daughter doesn't bring a screwdriver to prise it off before I find that damn fuse.
Brian