I have all hand made custom roof rack and lighting bar, Whats the best path to get wiring down to the engine compartment without dismantling headliner ect. I,m sure there are many options and many have already been down this path, Any advice would be appreciated.

 

Remove the plastic trim on the outside of the A-pillars. There is a thread on it somewhere here. You can route your wiring right behind it down below the hood cowls and into the engine. As from above, a small hole drilled can let you pass the wiring to the roof rails.