I have done a few mods on the G9 and it is quite different than the G4.
First here are some pics of the clamp. The first one is a picture of the open clamp, you can see there is much less room inside partly due to the smaller section along the bottom to accomodate the larger G9 unit and partly because Cardo went to a new method of mounting the microphone boom with a 3.5mm plug into the back of the unit. There are now 2 jacks inside from the factory, they are mounted on a small circuit board that stacks beneath the main board and has a very small connector between the boards.
Small bottom board with connectors:
Finished unit with jack bonded to clamp bottom:
I will do the mod for the same $30 price as the G4 mod, $5 shipping, $5 plug for the speakers option. It takes a little longer to do however because of the glue.
Email me for my address and to make arrangements: eileen.kelleher at gmail.com