Seems you are not another rebranded chinese import, congratulation for that.
Maybe you can help me answer some questions .
Is a carbon frame also shielding electro-magnetic waves? My assumption was it's like plastic.
Would it be a real hurdle to detach the GSM and GPS antenas from the PCB? I guess for GSM it's easy as remember trying it myself and it worked. But with GPS I had no success, that is not an ordinary piece of ellectronic. I am still thinking of the possibility to place just the antenas outside the frame and mask them somehow.
And are you using 3G or higher transfer standard?