You will need some sort of fine control to do so. A stepper motor might be better for such an application. Just turning a big AC (or DC) motor on and off will be very sloppy for this job. Is the car used old or new? Many newer cars are driven by wire with no real sterring column. You could hack the power steering instead.
Great thanks for this insightful reply, well in fact I think you are right, indeed it is possible to hack into the car. But still my question, I need a specific model of stepper motor as you recommending to use for such a task And in the same time to be controlled by picaxe