I have 2008 XLT Supercrew that didn't come with an overhead rail system. I purchased one from a wrecked F-150 on eBay recently, but I haven’t received it in the mail yet, so I can’t say what it comes with. For starters, am I going to need a new headliner or can I just cut holes in my existing one? Does it anchor to any metal in the roof structure or just to the molded headliner? I've also read on here that the rear of the headliner is secured with the back window. Is this true for an '08? Will I need to add wiring because of the added rear map lights (mine only as the front seat map lights and the middle of the cab dome light)? Any help is greatly appreciated.