Resting the camera on the dashboard of the car to keep it relatively stable would be a good approach. Then it's just the car's movement and the cars outside that will create the blur and not camera shake. This will have to be experimental as far as shutter speeds and exposure are concerned. Obviously night time would work best if I am going to record light streaks. The camera pointing at back seat and kids with blur outside?
Whirl of StarsAmazing sky images from Australia-based photographer Lincoln Harrison who has been taking photos for less than two years. In Harrison's photos, the rotation of the Earth makes the stars appear as if they're traveling across the sky. exposure 30-60mins