While traveling up or down the major highways in your vehicle you see that great shot you'd like to have but you just don't have the time to stop and get out to take it or you flew past so fast and the next exit is 20 miles down the road before you can turn around... Well here's how to get it.
First, you'll need someone else to drive the vehicle for you. Do not try to take photographs yourself while driving, it is dangerous and is most likely to be against the law in some states.
Secondly, it's best if you can be in the rear seat so you have access to each side of the road. You really don't wanna shoot through the windows because of reflections and exposure issues. If your window is tinted it will block some of the light getting to the lens thus causing slow shutter speeds (shake) and/or loss of depth of field. If your window is clear and you have no other way choice but to shoot through the window put the lens up to the glass where it is almost touching it. The preferred way though is to lower the window. Do not let the lens touch the window or door frame of the vehicle, hold it in your hands just like you would for any other shot. You don't want the vibration from the vehicle to cause your camera to shake and ruin your picture.
Thirdly, set your camera on shutter priority and dial it in to a preferred 1/500th of a second. 1/250th of a second may work but 1/500th is the preferred speed. Some people like the special effect of motion, slower shutter speeds will give that effect but the better way is to shoot it sharp (fast shutter speeds) and use post editing programs with motion/blur filters and create the effect precisely the way you'd like it.
Fourth, set your ISO to 400, if it's a very bright day ISO 200 is fine.
Fifth, be ready and think ahead about whether you need to zoom in or zoom out the lens for the correct composition as you will have very little time to take your shot. Also be on the lookout for guard rails (use zoom to crop just above the rail), and telephone poles.
Sixth, as you will be limited to about only 2-3 seconds, which sounds like not enough time to get your shot but it really is, try to snap off at least a couple extra shots of your scene very quickly.
One last hint; don't take photographs of cars or of the occupants in cars passing by and etc., as it may incite a road-rage incident.
Now, just a quick recap; Have a driver, be in the rear seat with window down, shoot at 1/500th of a second, set the ISO at 400, think ahead, shoot 1-4 shots of the same scene, use your zoom for composition and refrain from shooting vehicles and its occupants.