Ok, here's what I've got on seatbelt positioning:
Top mounting hole is drilled in the centre of the raised section of the parcel shelf as shown in the pictures, and 7.5 inches from the back of the metal seat support. Needs to be pretty central so the mounting point backing plate will sit flat against the parcel shelf sheet metal (very important).
The hole position wasn't worked out by me, it was worked out by the seat belt installer that I bought the rear belts from who did a series of measurements while using me sitting in the back seat as a test subject. I mention this because there are ADR's that govern the parameters of the mounting point positioning, and this guy seemed to know what he was doing. I made a specific point to ask my VASS engineer if the rear belts were ok and he said they were fine. The belts when installed in this position fall perfectly across the shoulder without cutting into the neck or falling off the side of the shoulder. Found I didn't have any info regarding the belt part number, but it is a standard Hemco parcel shelf retractable belt:
Drilled a small pilot hole up from the bottom so I could see where it came out on the top of the parcel shelf, then used a knife to cut a small hole in the shelf carpet for a spacer and spring washer to sit in. Then drilled it the full size to fit the bolt:
Got someone to hold the backing plate in position in the boot (plate bought from the seatbelt seller) while screwing the bolt in from the top. Once secure drill and rivet the plate in place so if you have to take the belts out the plate won't fall into the boot:
For the bottom outer mounting point I cut a bit of 2" x 2" x 4mm thick (cut 2" long) angle iron and drilled two holes in it (one on each face); one to bolt the angle to the factory mounting hole in the floor and the other to bolt the end of the seat belt to. I didn't bolt the belt end directly to the factory mounting point because the shape of the metal buckle on the belt was more suited to being attached to a vertical surface than a horizontal surface - also because the angle bracket helped position the belt better to where it comes out of the plastic arm rest slot. No pictures of this at the moment, but next time I have the armrest panel off I'll take one. For the single inner belt I used the factory mounting point with a spacer between the floor and the metal mounting buckle. Here is the finished result:
Also a bit of info on the front belts; info from the receipt says they are "Item number 1790001SP 99/90° (9 degree) Inertia L/S with 200 Drop Link and 1765333 300mm Stalks" (also from Hemco, bought the front ones directly from their factory in Ballarat):
The actual angle between the top and bottom mounting points is about 15°, and it can be seen in the second from bottom picture that the belt is exiting out of the retractor at a slight angle. The 9° retractor mech is used because when the belt is being extended and in use the belt actually pulls forward by about 5° and it doesn't bind on the sides of the mechanism as it's coming out.
I put a bit more seat belt info in this thread a little while ago:
http://mustang.org.au/forum/viewthread.php?tid=13284Edit 27/2/11 - Rear seat belt installation pictures showing drilled angle plate. Hemco part number for rear lap/sash retractables is 1790003:
