Abstract: A LED light source assembly, utilizing a standard electrical socket with an integrated heat sink and an adjustable secondary heat sink structure is described. The LED light source assembly places a LED light source at a similar relative position inside a lamp housing as a traditional incandescent light bulb, to take advantage of traditional reflector geometries. A heat sink is attached to an automobile electrical socket, having a standard shape for traditional incandescent lighting. A LED light source is installed on the heat sink, and receives electricity from the automobile via the electrical socket. A secondary LED heat sink, with a second LED light source, may optionally be affixed to one of several possible attachment points of the LED light source assembly. The addition of a secondary LED heat sink allows the number and position of LED light sources to be varied according to lighting requirements.