Here are the items that are available separately from #1 the entire stowage assembly. If not listed below, it is part of the assembly #1.
9 microswitch you can buy by itself
15 bolt
16 bracket left or right side
17 nut
20 flap
21 and 22 hinge left and right
23 bolt
24 trim handle
25 handle
26 and 27 use #35 (small parts kit)
28 clamp
29 bolt
31 bolt
32 clamp
33 use #34 (it's a sticker)
35 small parts kit

 

Jeff, Thanks for all your help. I thought the broken part was #16 but now I am not so sure. Does 16 fit on top of the other panels (#2 & 3) like the cover and have the barrel shaped (like macaroni) aspect that I assume held the cable in place? (see the photos I have attached). In the diagram, all three panels seem to have a smooth, narrow, flat top surface. I want to take it all apart but fear I may mess up something like the gear/pulley & have an even bigger problem. Seems that is the only way to really see what needs replacing/fixing. I hope the photos help you help me id the needed panel.
DJ

 

I am not sure, but I did google the part number and found actual pictures of the left and right panels, which I believe do mount vertically, not horizontally. The left one is 8H0-813-383 and the right side is 8H0-813-384, put it in with and without the dashes and you'll get different views. I am thinking it won't have the part on it that you need to mount the cable. The 2 part numbers are item 16 but the left is shown in the diagram but there is a right side #16 on your car that isn't shown in the diagram.

 

Hi, my 2004 a4 cabriolet top partially opens and i believe its because the trunk luggage tray isn't fully down. I had some stuff in my trunk on the weekend that was pushing it up. Here's a photo of the driver's side (not down but i think it needs to be). The passenger side is fully down. Does anyone know how to get the driver's side down? Do i have to rip open the side compartment? Many thanks

P.S. the lever broke many years ago, so its always in a down position and has worked fine ever since

Here's the photo https://ibb.co/hjoEZa[/IMG

 

I fixed mine with a £1 strip of aluminium, in less than half hour.

 

I have just fiexd mine with some copper wire .
Lashed cable to a local bolt. Works a treat!
Local Audi dealer quote £750 !!