I'm thinking of adding LED lights in the section of the lower grill that has a separate panel that I'll call the "brake cooling vent area". this removable trim piece will support an LED light strip. Does anyone have any information on using the "run relay" output or something similar for the power source?

 

Search for 'DRL controller' on eBay or the like. They have several of them. Most will turn on automatically when the engine starts (some sense vibrations, others sense voltage increase, personally I like the latter). Some will dim with the head lights, dim the side with the turn signal, etc... It'll do what you need... Just keep in mind that a lot of them are from China, which isn't a problem, just will take a while to get to you...