New old kid... just joined. Intro and a Q.

Welcome.
As to nav, as suggested the best option is to use your phone. Google maps, Apple maps and Waze are all pretty good. BTW, I like the built in nav and have zero issue entering destinations but of course you can't do this as you drive as you can't with a phone.

 

Nice plunge man! Thank you for your service sir. Next, priorititze your mods. I cannot over state the benefit of OVtune but read and make your own decision. There's alot of potential under that hood. Both port and direct injection, forged crank and rods, VVT, etc,acoustic valve timing, etc. Way more important than investing in navigation to me. But I understand your question. I believe all body harness's are the same so you should be able to hook up options that were not standard on your build. A new head unit would be the easiest path I can think of.