Dealer wants $215 + tax for disc including installation (not that there's much to install) for the lastest version. Worth it? Sewell wants $199. I told sewell that it was a 2006 and he gave me the part# of PT219GEN2309. According to a Sewell Nav Disc Chart that I found afterwards, that part number is for generation 2/3e Navs.
It says that a 2006 Sc 430 is a generation 4 Nav and the part is PT219GEN04-09.