I have seen MANY who wished they had held out for the factory nav or wished they did have it. if your talking a used car then the difference in price is wel worth the smal difference, on a new one the $$$ difference is quite a bit more, depends how good you are at customizing & what it is you are & aren't willing to accept, but overall I'd recommend getting the nav for sure at least on an 03-05, cause the non nav's don't even have a color screen & are much harder to retrofit an aftermarket than the 06+'s which even without nav do have a color screen at least that is a bit easier to add an aftermarket solution afterwards...