The flying buttress braces (on the left and right sides) add important rigidity to the truck bed sides via a “sandwich” mount that incorporates the rear seat belt anchor plate (on top of the fender arch) and the rounded fender sheet metal underneath.
Getting the flying buttress positioned properly is a little tricky. To ease the way, first remove the small stud protruding into the fender well area; it is spot welded almost directly below the bolt and welded nut when the seat belt anchor plate is folded over. Bending the stud back and forth a few times should loosen it enough to be pulled out.
Trim the seat belt anchor plate as shown in the illustration. This facilitates the proper positioning of the flying buttress brace. If not sufficiently trimmed, the seat belt plate conflicts with the bend in the buttress brace.
Bend the anchor plate down a little less than 90 degrees.
Trial fit the buttress to make sure that the single pierce in the aluminum is directly under the welded nut on the anchor.
The flying buttress brace is sandwiched between the folded over seat belt anchor plate and the fender arch sheet metal.
To get the best fit, two spacers between the layers may be required — the Smyth Ute kit provides only the primary spacer — so a secondary one with a wedge shape can be fabricated to exactly fit the remaining gap (not all vehicles are the same). PVC is a good material for spacers since it handles wet environments well and is easy to work with.
Drill 1/2″ holes in both the primary and secondary spacers for the 7/16-20 bolt.
Note that the Beetle seat belt bolts are SAE 7/16-20, not metric!
While these bolts fit the welded nut, they tend to be just too short (top bolt in photo) to adequately mount the flying buttress so longer ones will likely be required.
After the entire bed frame is adjusted and secured in its final location, test fit the flying buttress brace again. Make any spacer adjustments necessary and tighten down the seat belt bolt. The resulting sandwich mount should be extremely rigid and prevent any side wall flexing.
When the flying buttress brace is fit correctly, bolt or rivet the side wall top cap edge and brace together.