This was discussed previously, and I figured I'd take a stab at making a small lighting controller for passenger car LED lighting.
The module features an adjustable constant current source from around 5ma to around 45ma. This will allow you to vary the lighting in a typical 15" to 21" passenger car from very low to practically sunlight using the 12V LED self-adhesive strips. There is a small pot to adjust the current. The module also has a 22uh choke for DCS compatibility.
The size is 1" x 1/2" and about 1" high with the capacitor. The capacitor can be mounted to lay flat to the side of the module if that suits the installation better.