6 speed manual for MRS

Hi all,

Does anyone know why '03 and newer european MRs come with a standard 6 speed manual (which is said to be in fact a 5+1) when US models only offer 5 speed manual or 6 speed sequential ? Are they different gearboxes or is it just a marketing issue where they make it a "6th gear" in Europe and an overdrive here ? That question has been bugging me...