OnStar is NOT why Nav is not available...
NAV is an available option on Many (but not all) GM cars even with OnStar. That said, there is probably some other reason why there is no Nav option (They liked the dash design as is and didnt want to clutter it with a screen there? who knows....). I don't know what it is, but i probably wouldn't have gotten it anyway.
2010 Chevrolet Camaro SS - was daily driver, now toy
2014 Mercedes Benz E350 4matic Sport - Daily Driver
2008 Chevy Silverado 2500 HD LT 6.0 - Tow Vehicle
1995 Volkswagen Golf Race Car
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