I suspect the subwoofer is the issue. Not sure how the trims affect the trunk layout in Canada and U.K.Well I went and tried mine after work, and I was able to lift the False Floor (not the flap to the spare) and I was able to lay my cover down face up inside there. I am wondering if the space is different between The GS and the GT Level. Maybe the spare and the Bose subwoofer take up more space??