I just installed a roof rack. I am going to put lights on the rack. My questions are about the wiring installation.

Has anyone drilled a hole in their roof to run the wires?
How did you prevent leaks?(If you did prevent them)
Does anyone have any tricks I should know about?

I intend to use a grommet and flowable silicon. If anyone knows another way or other items to use please let me know.

I am going thru the roof because I dont feel like running the wires all the way from the front of the truck along the roof to the tailgate.

Does anyone know of any websites that I can get picutres or info on how best to prevent leaks?

Thanks.