I'm not sure if this would help, but you should be able to run 10 bits with no problem. The standard bits and clones have 27, 35, 40, 45, 49 and 57mhz while the super bit char-g's use 3 frequencies varied at 27mhz and 3 frequencies varied at 49mhz.

The variable resistor on the pcb of the car (the component with the coils) has a tiny screw that you can adjust which controls the frequency of the car. Trying to alter the frequency of the car can only be done by replacing or modifying this variable resistor.

Would you by chance know how to unsolder a component like that off of a bit PCB? The variable resistor has four solder points, so I would have to remove the solder somehow. An EE colleague at work mentioned a small spring loaded vacuum (shaped like a pen) that sucks up the solder when activated. Do you know any standard method like that to remove solder? I'm just an ME, not a sparky