I just bought a new HID conversion kit from ebay. Upon opening, I realized that the relay harness is not included in the package. Would anybody help me figure out whether I should have one for installation or I can go ahead and install without the relay harness

 

It depends on the kit. Some kits don't need a relay anymore. I got an HID conversion kit for my 05 which didn't need a relay. Just the bulbs and ballast. Best thing to do is call the manufacturer to confirm if you aren't sure.