Torn out nut insert on hatchback lift strut anchor

Question

Car: 2001 VW Golf

It was late at night, I was in a hurry and like an idiot I forced the hatchback closed. I tore out the nut insert (don't know what else to call it) that one end of the hydraulic lift strut anchors to.

Is there a way to replace the nut insert myself or is there some way I can hack the hole so that I can screw the bolt in? The strut bears a fair amount of weight so it would need to be a sturdy hack

The gaping hole where the "nut insert" used to be.

This is the other "good" end showing what the nut insert looks like:

Answer 1

I see the following possibilities:

1. Insert a rivet nut. That is a simple fix but there is a slight possibility that it won't hold.
2. Ask a bodyshop to weld the ball joint, ideally with an small reinforcement plate, to the car body. The definite solution, albeit expensive.

Answer 2

You could use a small triangular file to shape the existing hole into a female hex and use a hex rivnut.

Flat Head HEXNUT Body is provided in both a standard and heavy hex design. The heavy hex design features a larger body diameter that results in increased thread strength and torque capability. The hex body design provides the ultimate in spin-out resistance when used in a hex hole. The RIVNUT® is designed for use with Property class 5 mating hardware. A grip ID mark is included on the head of the fastener for grip range identification.
 _{source: RIVNUT® Flat Head Hex Body}

Rivet Nuts (aka RivNuts) are also available with a spline that holds the RivNut instead of a hex. If you go this route, you might have to drill the hole to the correct size.

Some RivNuts need an installation tool. Essentially, you tighten in a bolt that expands the bottom of the RivNut so it cannot escape the sheet metal hole. See the difference between the second and fourth image above.

I got familiar with this fastener when I installed some auxiliary bash/skid plates under a Ram 1500 4×4 so as a fastener they can take a fair amount of stress.