Your roof will creak at some point in time and dependent on road surface and ambient temps. Mine will creak if the car has been sitting in full sun and then driving slowly on an uneven surface, however at speed on smooth roads its always been silent. Its just the nature of the beast. seperate panels and all the gubbins to make it work is bound to make the odd noise so long as not rattling. A combination of gummi phfledge and krytox usually works for me.
Tim.