trying to build bluetooth control control car via androide appliaction

hello , I am now doing my university project.This project is to build a wireless remote control Car.I want to use some funtionalities for my car design.

  1. Bluetooth control for driving car. (Forward,Backward,Turn left ,Turn right,Release).
    2 .Avoiding obstacle using Ultrasonic sensor.
  2. Horn and signal lights via LEDs

For above describe functionalities ,I use the following materials.The list are in below.

1.Arduino UNO board
2.L293D DC motor drive Shield
3.Bluetooth module (HC-06)
4.Ultrasonic sensor (HC-SR04)
5.Two DC motors
6.Speaker(8 ohm ) and LEDs

Firstly I tested without motor shiled and
controlled codes over bluetooth module (directly output from digital pins to motors ).It is work . But , When I use motor shield , it does not work .I can't receive or transmit datas over these modules.

According to my desire,I want to control my car using bluetooth over androide phone(by BlueStick control app ).But the bluetooth singal does not work when I am connecting with motor shiled.my Car design is four wheels using two DC motors.The first motor is using forward and backward.I found the code how to spin motor forward and backward.Another one is Turn left and right using the same function like as forward and backward because of hardware design.turn right and left only need to spin motor forward and backward.If possible I want codes that give the following actions..

. use the modules I described above
. Control two dc motors (only forward and backward )
. Signal lights for car (use when need to turn left or right )
. Brake lights when Release
. Car horn

I am a beginner and this is my first project.now I am trying to build myself.But the difficulties for a beginner are too much.This is because now I am requesting for help.thanks...