15 The backing plates for the lateral support anchors slip into place in the subframe, on the backside of the holes you see here. The anchors then bolt to them through the subframe holes.
16 We had to modify the anchors a little to get them to slip into place where they could be bolted to the anchors. With that done, they were bolted securely to their backing plates, sandwiching the subframe between the two parts. Trim the carpet around the anchor and start reinstalling interior panels.
17 The carpet does have to be trimmed around the lateral support anchor, but only slightly. Should you wish to remove the bar, this, and a pair of holes on the back deck, are the only things left behind.
18 The Shark Bar will mount to the bolt holes that would usually hold the retractor for factory shoulder belts; the bolts are easy enough to find once you peel back the carpet, as they are quite large.
19 After removing the bolts from their location under the carpet, we used an awl to probe through the carpet to find the bolt hole. We then opened up the hole so we could fit the harness-bar mounting bolt through it.
20 Once the included 0.5-inch bolt will fit through the carpet, put the bar in place and install the two bolts into the holes you located on the back deck. They’ll be torqued down later. For now, just install them, followed by the struts, with the Heim joints downwards.
21 The bar, braced and fully assembled. You’ll likely need to adjust the heim joint at the bottom of the strut rod to get the length correct. All bolts attached to the harness bar should be torqued to 25 lb-ft; all others, 30.
22 With the bar torqued down, the shoulder harnesses can be threaded into place on the bar, under the loop that keeps them from sliding too far to one side. Follow the mounting instructions: The end of the harness should run out of the slider, over the bar, back into it, and then be looped over the top of the slider and run back through.
23 The Vetteworks mounting bracket for an anti-submarine belt, which bolts into place on top of the brackets that hold the factory seats in place. Because it’s designed for stock buckets, it interfered with our A4s’ fore-aft adjustment bars. Fortunately it also allows you to route the belts over the front of the seat, which is what we’ll be doing.
24 In the absence of more-specific guidance from the NASA, SCCA, and other rulebooks, we chose to mount the anti-submarine belt to the seat bracket, which is made of welded flat stock and bolts to the seats’ factory mounting points.
25 Since it’s important for the anti-sub belt to be centered—to prevent your body from pivoting around it—we measured the seat bracket from side to side, and spotted a hole in the middle of the rear bracket.
26 We then used a series of drill bits to start the hole, gradually enlarging it to the required 0.5-inch. If you do this without removing the bracket from the seats, consider covering the seat to protect it and backing your hole with something like this piece of wood. This will keep you from punching your bit through the bottom of the seat when it breaks free.
27 With the holes drilled, we bolted the anti-submarine belt’s mounting tab to the mounting frame, again using a hardened 12mm bolt with a washer and nylock nut.
28 Unlike the lap and shoulder belts, which you cinch into place once they’re buckled, the anti-sub belt can’t be adjusted when you’re seated. We adjusted it for length before putting the seat back in the car.
29 All the belts in place after final assembly. All that’s left is to get in the seat and strap them on.