From what I have read the captive nuts for mounting are not installed (or the holes drilled) on low spec shells, so these need drilling and self tapping screws used. There are also not the cutouts for LX and Higher trim peices, so these again need fitting, which also then requires a longer rear seat belt upper mount bolt and spacer. I plan to fit without the extra trim though. There's a good guide on Cisco's. When I get round to it I'll probably do one for here.