C6 Factory NAV install after purchase

I have a 2006 C6 that has OnStar (3LT) but no factory NAV. I have seen a complete GM vette NAV system for sale but wonder what is involved here as far as an install goes. Is this simply a plug-and-play?? Anyone out there done this? Any advice or links to the install is greatly appreciated.

I have a Nav system in my 2006 vette ,I dont think it is as good as the after market such as ,Garmin,TomTom,Magellen ,not to mention the expense of installing a factory Nav with antenna.

I believe the question at hand relates to the potential or possibililty of installing an OEM unit, rather than the quality of various units.  I'm not a wrench-head, but electronics can be quirky.  It would be easiest, if the wiring harness has a pig-tail to accept the unit.  Have you asked your local Chevy dealer is this is something they have done ... have heard of ... or can do?  That would be the easiest step, and the best first step.  They may be able to give you a quick answer ... such as ... YES, but you have to replace "x" in the process.