Would it be possible to make a remote control car conrtolled be a cell phone?

Question

I was looking at radio transmitters and recievers on ebay and they aren't very cheap, so i started to think that i could get two prepaid cell phones cheaper and use them to transmitt the control commands, if i knew anything about electronics that is. I was thinkning that you could call one of the phones that would be hooked up to the rc car and then use the the keypad to make certain dial tones, where each tone would be a different command. The tone for 1 could give throttle and the tone for 2 could be the command to turn left and so on. Does anyone know if that is doable?

Answer 1

Phones don't "emit" much in the way of tonal variations from a phone call.  However, you could potentially text another phone, and use different letters as different commands, not unlike what many control systems do normally.

Being able to tap into the text messaging system, on the other hand, is nontrivial, particularly for someone who has zero expertise in the hardware or electronics.