This tutorial will teach you how to add lighting to a car. The lens filter is used for this effect and only two steps are required. I have used a free stock image of car which is available at: www.sxc.hu
Lighting a car
Open an image of a car in Photoshop.
Select Filter > Render > Lens filter and a window like below should appear. Now move the crosshair of flare center to the centre of the car light like in the image below. Set the brightness to 50% and the lens type to 105mm prime.
Repeat this for the other car light.
You should now have light on the car.