Radio Shack RC cars in only 2 frequencies

[jl2000]

I ordered 4 RC cars from radio shack to do some racing around the desks in my office. Unfortunatly I did not do proper research and to my dismay I learned that they only use 2 frequencies for the rc cars 27mhz and 49 mhz.

The worst part is they sent me 3 at 27mhz and 1 at 49mhz, those bastards.

So i took apart the controller and identified the resistor that controls the frequency. I did not feel motivated to taking apart the car yet, but I am assuming that thier is a simalar set up in the car.

What I really want to do is set up 2 of the cars at alternate frequencies so I can run all 4 at once. Is this worth my time?
If so what should I do?

thanks
jcl