vehicle standard asset input system to dual touch sideways moving input for mobile

I have started building a car racing game that i wanted to work for android mobile phones and unity standard assets made my work a lot easier but the input system that the car prefab provides is quite hard to convert to a dual touch sideways moving car...if anyone could provide the solution how i could achieve the car movement such that when i press left and right buttons the car would move accordingly. any input or hints would also be greatly appreciated.Car movement with four buttons would also be a great help if anyone could show me how to do that!!.Thanks!