When you hook up a SAFC do you have to have one of these wire harness, or can you just cut and splice everything in. From what i have read it seem slike everyone splices, but then i see wire harness like the one below.
http://cgi.ebay.com/ebaymotors...33553

Yes i know the above like is not for a honda, but i have seen then for hondas

 

No, you won't need a harness like the that. The installation can be done by splicing (I always recommend solder and shrink tubing on the connections). The only benefit of a harness such as the one you linked to is that it allows you to install the unit without cutting or modifying your vehicle's stock wiring. Not a huge issue, but some people are concerned about that.