UPDATE! If you are planning on using my modification to the MT case to mount the Fenvi WiFi card directly through the case by drilling holes.... DO so on the space NEARER to the PCIe slots... NOT near the PSU. I WILL UPDATE my post momentarily.
1) Choosing the side nearer will mean shorter length of ribbon cable is needed.
2) The original location I suggested is too tight on the ribbon cable and the ribbon cable WILL get caught in the GPU fan! I discovered this only when I opened up the MT recently to add ram and found the PCIe extension ribbon cable had been caught by one of the GPU fan blades! It seized up that fan.
Follow this new way and you can ensure you have plenty of ribbon and can secure it away from the fan blades.