Yup I recall looking into this when someone asked about the space-saver a while back, there are several different configurations and j-bolt mounting points, depending on coupe, convertible, full-size and space-saver. I think on the coupe with full-sized spare, the L-bracket near the center of the rear seat back locates the jack mast and the outboard end just relies on the clamping force of the spare secured above it stopping it from moving/rattling, like Jimmy said above.
