This project was shared on the website 43oh.com which is project for beginners. The controlling of RC car is controlled with a bluetooth module.
The basis of the project is MSP430G2553 microcontroller which comunicates with a HC-06 bluetooth module through an UART.
The microcontroller controls the RX2 circuit which controls a motor.
You can find the source code for microcontroller on the website and you can donwload (only for logged users) app for an Android.

http://forum.43oh.com/topic/5484-controlling-a-rc-car-w-bluetooth-connection-speech-recognition/