8 foot 1/16 SS or Galvanized Steel Cable.
8 foot 1/16 ID UV resistant Vinyl or Silicone tubing.
4 1/16 ferrules.
or 8 foot vinyl coated 1/16 SS cable.
1 foot Flat Brass Chain you only need 4 links total, but you have spare if you mess up

Start by cutting the cable and the vinyl tubing in half. and cutting 2 links off the flat brass chain.
There are 2 styles of attachment points for the different frames that VW used. Knowing which ones you have determine the length of the Cable when complete.
The older Style attaches at the padding Bar. The length of these cables are "Loop to Loop" 40". The Spring attaches to the front of the frames padding bar. No Brass Chain is needed.

The Newer Style attaches to a Stud at the side of the front frame. The length of these cables are "Loop to Loop" 37 1/4" to no more than 37 1/2" or from loop to end of brass chain. Spring is at the rear.

Take a ferrule and thread it on to one side of the cable, then place the chain not the flat side on the cable loop the free end back to the other ferrules side, pull the long side tight, make sure that the chain is in the loop and that the bitter end of the chain is inside of the ferrule.

Then using a AMP tool or a pair of pliers compress the ferrule.

The cable should not have any strands of wire sticking out of the ferrule.

Now Get a board I happen to have a Carport rail.
Hammer a nail in to the board.
Using a Tape measure measure over 37 1/4 inches and drive another nail in to the board.

Take your one end that is finished and hook it over one of the nails.
To the other nail hook your plumbers chain over it and pull it out to lay flat.
Take your vinyl tube and measure it from the ferrule end of the finished end to just about 1/4 inch from the plumbers chain and cut it.

Insert the cable into the vinyl tube.

Place the ferrule on the cable, then thread the cable through the eye of the brass chain.

Put the free cable end back in to the ferrule and pull tight

Using a sharpie Mark the cable free end on both sides of the ferrule.

Take the brass chain off the nail and cut the free cable to the ferrule side of the mark.
Push the cable back to the mark that is on the eyelet side of the ferrule, there should be no bitter end or strands sticking out.
Then Crimp.

You should now have a cable that is 37 1/4 inch long with pivotable brass chain strain relief....

Be sure that you use a Nail Set, Center Punch or similar tool to widen the flat end of the brass so it can go over the
teat of the cable holder in front.

Enjoy
I have added this already to my replacing your top guide.