I have the same setup as described by the original poster. Trouble is I am running 2 x 55w Spot Halogen lights and the factory wiring from the reverse light isn't adequate. The lights are noticeably dimmer when powered by the reverse wiring.

I am not very savvy when it comes to electrickery and would appreciate some help (in layman's terms) how I can solve the issue. Obviously I need to use a relay, but how do I wire it?

Here is the caveman setup I currently have. Feel free to scribble on it and post back! Thanks

rearlight.png