Very interesting finding. Please keep us posted. (Already bought the LeatherZ but it is good to have alternatives).
Some folks had mentioned at one point using an X3 spare. Have you looked into it?
E91 328xi, Jet Black, Black Dakota, Dark Burl, Premium, Steptronic, Navigation, Active Cruise, Park Distance Control, Sirius Satellite Radio. Debadged, Euro Switch, Dome Strut.