Answer:
I cause involuntary movements in your vehicle
I am in the past never in the future. I don't exist but have existed. I saw what you saw and that is what I will ever see.
I hold two meanings. With one I may be broken with the other I hold on.
Though desert men once called me God today men call me mad. For I wag my tail when I am angry. And growl when I am glad.
What is always in front of you but can't be seen?
When is it bad luck to see a black cat?