Besides stud conversion and lug nuts, is there any alternative for mounting non-Volvo wheels with flat or mag shank holes? Local tire shop will not mount wheels using stud conversion, saying it is unsafe. The S80 5x108 bolts are 14mm x 1.5 with a coned taper, meaning the existing bolts don't fit other 5x108 bolt holes without conical shaped seat. I would think there is some bolt alternative or adapter, but haven't found any. I tried calling IPD who say they only sell a stud conversion kit (and assure me it is safe). Anyone know of a different solution?