66cruiser, was not worried about you being able to do the deed, just that if you BUY a KIT it should be complete and if the proper R&D was done, there should be no cutting and splicing required by the end user to install. Why would (or should) you pay the premium and STILL have to worry about cutting, splicing etc. and personally provision wiring/connection from water intrusion, corrosion, electrical tape turning to goo (if you did not use heatshrink and seal the ends w/sealer), etc.
Knowing a bit about electronics engineering and track record of manufacterers for customer service, it just does not make sense to leave that part of the installation to chance. What it does is provide a nice out for manufacturer if warranty issues come up..."--did you install it properly...I'm so sorry, we guarantee the unit to be free from defects at the time of manufactur...blah blah...?"