Open an image of a car. Here is mine:
Make a new layer above the car layer and fill it with black. Your layers should look like this:
Now go to Filter>Render>Lens Flare and make a Lens flare 105mm Prime with 100% Brightness.
Now put the layer in "Screen" mode. Your image will look like this:
With the Move tool, (V on keyboard), move the layer until your lens flare will cover a car light.
Do the same with the second lens flare, on a new layer. Merge the lens flare layers. Your image should look like this, with this layer palette:
Now, with the lens flare layer selected, go to Image>Adjustments>Hue/Saturation (or hit CTRL+U on windows, Command+U on Mac). Mark the Colorize box and give the lights your desired color Here are my values: Hue:221, Saturation: 22, Lightness:0
You’re done!
