The company I used, MVI, is found under gm-navigation.com . I had a non-navigation, no HD radio in my Impala (which is a Factory CNG equipped vehicle---only 200 built so I had no option choices). The total cost was $1460 broken down as $220 for the Car Play module, $820 for the Navigation module/with Car Play and HD radio, $60 for the USB port (the Impala had a SD card port that wasn't compatible), and finally (and not needed) $300 for the unlock and mod for in motion video and touch screen control. Like I said, everything including the Nav antenna cable was provided along with an installation video. Basically remove and re-install the modules. The GPS antenna cable was the hardest part of the install as a lot of trim needed to be removed. Wrapped it up, turned on the key and everything powered up and worked like it came from the factory! There are other vendors out there that provide a similar or the same service but this one had been recommended to me and as far as I am concerned, a good choice. With the integration of the radio with the rest of the car, I thought this route would be a better move as a high end, Car Play enabled radio is pretty pricy on its own. If you are only interested in Car Play, the price will be a lot less than I paid.