What emotion do you feel when when you see the car? Do you get any memories? Perhaps something happened in your past that involves a car and the image evokes the feelings that that memory had...
Only you can answer this question. Try to analyze how you feel when you see a car, what is your impulse of doing (i.e. to run away from it, to go towards it, etc).
Bottom Line: only YOU have the answer and once you look deep and find the answer, you can find a solution on how to overcome this.