I have a 98 A6 that has the hot climate sunroof/solar panel. On the inside of the car there is a panel that covers the sun roof that slides back with the roof. By design it does not slide separately from the solar panel like standard sun roofs. It is mounted to the solar panel via a bracket which the small blower motor is mounted to.
That bracket broke and now the cover panel jams when the panel is being closed. Along the front side of the lower panel is a plastic vent that runs the width of the panel. That allows the hot air to be vented out. That is broken as well and I need to find the part number for it as well as the bracket.

Does anyone know what the part number is for both parts and where I can find them?

 

I have the same set up on my 1998. Just to clarify. You are right the panel is fixed because the sun roof does not allow any light through, so you would never need to pull back the sunroof panel. The vents are not related to the solar function, those are the same on all A6s, they just allow air flow when the roof is in the "tilt" position, ie the back of the sunroof is up.
The solar roof simply sends power to the blower motor, which turns at low speed and pushes outside air into the car. It might be like leaving your two front windows open 1/2 an inch?

I think you need to go to the dealer with your VIN and get the part number, or an audi junkyard that can look that up. I am not sure if it is the same part, but just fixed or a different part. Sorry not to be specific to your question, but those solar options are rare so easy to get the wrong parts.
Can you remove the panel and see if the sunroof is working properly. I wonder if the sunroof had some issue, like a part broke and then when opened caused the panel to break.

 

I've got photos of the sunroof diagram with part numbers. I'm not able to post them here because the files are to large. Can you post an email address and I can send them to you?