What glue do I need to use to adhere rear window to convertible top? It is pulling away and I cannot afford a new top just because the glass is pulling away.

This is a common problem. At the factory, the top material is bonded to the glass. That bond is breaking down. You can use Gorilla taps or urethane adhesive, but you will eventually need a new window unit.
The window unit is separate from the actual top. The top must be partially removed to replace the window unit.

Karl at aoksales.com

I had the same problem with the window in my 2003 beetle convertible. I purchased 3m windo-weld super fast A10E2A and single step glass primer A13B5A also 3m. I ordered it online from Auto Body Toolmart. It was very easy to do and is in there really tight. Unlatch the top just enought to release the tension.
1. clean the window and remover any old glue with a razor blade
2. use acetone to make sure the rim around the glass is clean
3. apply thr gass primer and let dry
4. apply the glue which is black so put on a thin bead and I used gloves so I could make sure it was on both the window and also the fabric of the top. You must work fast because it sets up in 15 minutes.
5. Then take blue masking tape and secure the glass by taping all around the top. up and down and from side to side.
6. allow to dry for 6 to 12 hours. the clean off any extra glue with a razor.
The total cost was $39 dollars instead of having to buy a new tp

araldite ,epoxy resin two pack type adhesive

I have the same problem and read that in some cases 3M Wind-o-weld has been used to fix it. I tried that, and as soon as I put the top down and back up, it pulled back away. looks like I'll be getting a new top

there is actually a tsb on this and the dealership should handle this concern

I used gorilla glue and it has been holding for over a year now!

Here is an idea!

This problem is very common and is known as delamination.
Use Urethane adhesive to reglue the window.
This same adhesive is used to install windshields.
The hard part will be to hold the window in place till the Urethane cures.
Prepare for that in advance.

Karl at Topgunwon.com

It worked. Still very stuck with no signs of coming loose and I did it about a month ago. Just dont use too much and apply it with a little paint brush like an artist would use. You can always add more, but if you use too much, it will look messy. I used a little much in two places and when it expanded, you could see the yellow foam it makes at the edge of the fabric. But I just shaved it off with a razor blade and it looks fine. After doing the outside, gluing the glass to the fabric, i also glued the headliner in place as well. I lowered the top a few inches to take the pressure off, and put just a little glue in the track around the inside of the window, then put the edge of the headliner in the track. Left it overnight and it has not come loose since. I think getting this headliner reattached is important cause the headliner actually pulls the glass against the fabric top, which takes pressure off of the glue holding the window in place. In retrospect, maybe if i had fixed the headliner earlier, the window might not have come unglued in the first place. Shame on VW for not dealing with this issue better. Replacing the entire top is ridiculous!

I have the same problem. I got acetone and removed the old glue from the glass. Then  I reglued it with gorilla glue. This stuff explands into this yellow hard foam, so you have to be careful not to put on too much and not to get it on the outside of the top. I stuffed the back window area inside the car with pillows to push the glass up, then carefully applied the glue to the edge of the glass with a paintbrush. Then I covered the glued area on the outside with plastic bags of kitty litter to hold the fabric against the glass. Takes 4-5 hours to dry. Worked beautifully so far. Got a little thick and a couple places and I removed the excess with a razor blade. Then on the inside, I applied a small amount of the same glue with a paintbrush to the inside of the little track round the window. Then inserted the edge of the headliner into the track. Did all of this work with the top slightly opened to take the pressure off. So far so good. One week and counting. Hopefully it will hold up to the heat and sun.