mounting needs wet and drying to fit frame rail, then piece of 20mm round stock cut to fill gap between bracket and seat, drill and tap 6mm, tap 6mm stud and loctite into mounting, tighten round stock onto it, drill seat base, drill and tap round stock, drill fibreglass unit and fasten on with 6mm dome heads, drill and tap bottom of mounting, make cross strap and fasten between frame rails to stop subframe moving, starting to get the amount of work you need to build something like this yet?