I was hoping this would be so much easier, but I decided that I wanted to try something new. So, I waited until it got dark this evening and headed out to try to take pictures as the cars went by. I got some shots that were much clearer than this one, but this is the one that showed the movement I gave it by slightly moving the camera. I shot this in "bulb" mode and covered the lens with a baseball cap between the cars driving by so that I would have more than one set of lights, but because I wanted to show a bit of movement too, I also give the camera a very slight movement to show the lines jumping around.
(F 5.6, 59 seconds, ISO 200, 300mm)