I'm really going to have to blog about why Android is not going to work for carpc's. but here's a preview:
Firstly, Linux is an ecosystem of hundreds of companies, projects and people working in a symbioses. Anything anyone does to improve their little portion of Linux benefits everyone else. For example when Intel's moblin project improves booting for mobile devices, amazingly enough, my desktop, servers, and every other Linux device started booting faster. Imagine that!!?
Subsequently, things i develop for linux have the potential to run on other linux devices. nGhost can run on my n900 phone. The maemo 5 on-screen-keyboard can run in my car. GPS and media subsystems are the same from the desktop to the server to the car to the phone.
Android is based on Linux, but it's not Linux. Everything android does to improve itself helps noone but android. Apps developed for android don't run on my ubuntu desktop, they can't run in my car. Android takes from the Linux ecosystem and gives literally nothing back.
Google nav will never come to your PC. the x86 version of of android is *banned* from using the android app store. Even if you could get google nav (illegally), android is meant to work with a non-standard gps subsystem which likely doesn't support your bu-353 or your wifi card, or your 3G modem etc.
Android devices may be created for the car, but that won't mean you will be able to run android in your car without that device.