On short film "Yours Truly" there was a night scene that took place in a moving vehicle. The budget did not accommodate a process trailer, so we decided to create the shot using a "poor man's process" setup.
The breakdown of the lighting involved a few levels. Ambient light, street lamp, headlights from behind, and light from passing cars.
Our ambient was achieved with two kinos, one for each person in the car. In addition to a 4 bank kino on a goal post to add a slight "moon" edge inside the car.
The street lamp was a lot of fun to recreate. We used a rotation lighting boom on a combo stand in conjunction with a dimmer to create the illusion of driving by the light. On the boom was a tungsten 1k with a sodium vapor gel. It was important to use black wrap to reduce any reflection of the lighting fixture.
The rear headlights were achieved with two Arri 150w fresnel lights. Their barn doors were closed almost all the way to reduce the size of the light. Finally, the passing car gag was created using an Arri 300w, hand held swinging by the side of the passenger.