Hi all. I suspect that anyone who has a cabriolet is going to have the same problem as I did sooner or later. The short version is that the screws that hold the cabin lights/motion detector/soft top latching location came loose in a fatal way. The original screws were self tappers that screwed into a ****ty little nut that is irretrievably embedded into the windshields metal frame. The factory nut looks like it was designed with slits in the side so that it can be pushed up through the hole and then expands when the screw is driven in. However it was installed, the nuts were stuck in there and had expanded to the point that the screw would no longer hold. As soon as I saw the problem, I saw the solution. It's not tricky at all and on a scale of 1 to 10 for degree of difficulty, I would put it at a 3. The key is threaded rivets. I use these little guys in my security business to affix access control locking system crash bars to exit doors.
The way it works is the aluminum threaded rivet is compressed by the bolt while the nut, which has some small teeth on it holds the collapsing rivet in place. You hold the nut with a wrench as you turn the bolt and after a few turns, you have collapsed the aluminum rivet to a degree that it hold tightly in place. After a tiny bit of drilling, a 3/8" rivet fit perfectly. The whole did not need drilling, the old nut did though in order for the rivet to fit in. A bit of coaxing with a small hammer was also needed. I wanted a tight fit.

A few pointers.

Drill very slowly. The bit is going to want to catch in the threads and quickly get drawn up in the whole. Hold back firmly on the drill and be prepared to let off of the trigger if it starts to take off on its own. You wouldn't want to drill through the window frame.
When compressing the rivet make sure that it is on the same angle as the what the new screw is going to be when it is run up through the cabin light/motion detector/roof latch thingy.
Do not over-tighten the new screw. You ARE strong enough to cause these rivets to spin in place. Once that happens, you will have to drill it out and start over. Drilling the rivet out when it's spinning would be no easy task. It would probably take you as long to extract it as the whole rest of the job.
Do not use Lock Tight blue or red. If you need to get the unit down the Lock Tight will hold it so well that the rivet will begin to spin. That would be even a bigger problem than what I described above.

Heres a similar rig to the one that I used. http://www.mscdirect.com/product/06855902?fromRR=Y
Harbor Freight has a kit that they sell for under $20. I'm not to sure about their riveting tool though.
I used the longer screws pictured because I had them and they weren't too long to fit.

Well, here you have it. That about sums it up.

Next is a built in garage remote with a release button on the dash!

Here is link to some photos. https://www.6speedonline.com/g/picture/197620

 

I had the same problem on my cab except with the nuts embedded in the window frame that hold the latch points for the top on. There is a great write up on how to do this over here: https://sites.google.com/site/mikefo...andrcenternuts . Whole problem is a PITA. Porsche did NOT make a good call when they picked the weak nuts they did to embed in the windshield frame.

 

Excellent write up. Same method, same result but their write up was better documented. Thanks.

 

No problem. The only issue I had with their method was with the modification of the Riveting tool so that it could handle 6mm (?) rivet nuts. I put a 100m long threaded bolt (without a head) in the tool but it kept bending and messing up the tool. It would work once or twice and then be too messed up to work again. I was able to fix one bad nut in the car but left the rest for another time (until they break I guess).

 

I hear that. I would replace them all if the windshield was out. If you take a look at the pics that I posted, the solution that i used had a nut and an hex wrench. It took a bit of leverage but it allowed for the larger screw. I didn't like the looks of using the riveting tool form harbor freight. It looked flimsy.