The relay/fuse are basically optional ($60 more). This gives you more protection
not to overload the OEM wire harness - Specially when yours has an HID fog
too. Imagine having both on for awhile. But yours seems to work so far.
The direct connection to the battery will saves you from having problem with
the OEM wires that also connects to some other electrical system. Sometimes
current fluctuates and causes overload and mess up the car system. Having a
direct connection to the battery is an insurance that you`ll only messing up a
5 cents fuse when overload occurs. Basically, it protects your OEM electrical
system in the future.
This is what I`ll get
http://www.lightwerkz.net/prod_harness.htm