NewSense wrote:
The Airport Extreme A1027 card works in the PCIe PowerMac G5s, as there is still the residual Airport Extreme input slot on the board, just below the PCIe slot frame, but towards the back of the device, you just have to know (be careful) which way to insert (orient) the card as there are no metal support guides in front of it as there are on the earlier PowerMac G5 models. I know this works as I fitted one for a friend using the antenna lead from an A1106 (IIRC) as the intermediate connector to connect it to the built-in antenna leads already inside the PCIe model PowerMac G5s.

I think I supported the Airport card with a DIY plastic frame fastened (hot-melt-glue, or such-like) to the main part of the case. I can't remember how I supported it, but I know I made it sturdy enough to be OK.

Then I bypassed the Runway, (Hen's Teeth) virtually impossible to obtain, dual interface card, and just fitted a Bluetooth dongle (the small semi circular USB connectors) that you used to see fitted in the side of laptops, and just put that in one of the USB slots, that way I also added Bluetooth to the PowerMac G5 PCIe model (I think it was an A1177). Some of the dongles may not work, and you have to choose the older models that worked with Windows XP and 2000 I seem to remember, but it worked OK, as I tested it with my Apple A1016 keyboard and a basic bluetooth mouse.

Hope this helps.