I Know I Know...

Alright, I have my Pro Design kill switch in hand. The dealer said to tap into the black/yellow wire under the front fender. I read on here to tap into the white wire under the seat. Which is correct and what are the differences? Also, if I tap into the wire under the seat, will I have to add any additional wire to make it reach? I'm concerned that when I turn my bars it may come loose? Any links or a simple answer will help greatly. Thanks in advance.