[BR3W CITY]

You can absolutely do this, its just that certain concessions have to be made. This is basically the reason that Android Auto and AppleCarplay units exist. They are head units that mirror certain smartphone functions and allow for GPS, Streaming media, and mobile connectivity. I have an NEX4200 in my Yukon.

What you want to do, is effectively gain that functionality, without the use of another head unit (instead using the tab AS the unit)...but that means you need to find additional hardware to aid in the setup.

Running audio output through the Usb-micro that most phones have as a charging and data port, allows for normalized audio output levels. People run into issues with this if their ROM has a built-in audio booster/eq device. This is actually a good reason to flash a custom ROM onto the tablet being used. You can remove junk and run a "car friendly" ROM with larger touch inputs and things like EQ function easily accessible.

Using a USB-micro to AV cable, you can get full audio output to RCA audio, allowing you to go IN to an AMP. Again, because it isn't a "true" line level and may be subject to apps messing with the audio, its best to install a modified ROM which will remove those prepacked functions. This also means that there isn't a safety net on the audio output level, which you'll have to be cautious of if you plan on using a variety of audio sources or plan on playing media from memory instead of a streaming service.

The other bonus to running that way is the benefit of the connection itself. The RCA's can be run through a line-level volume knob which you can dash or console mount. You REALLY DON'T want to rely on a touch-driven audio slider, as an error can cause your audio to become erratic (or as mentioned above, a huge change in output volume could damn near deafen ya). The other part being that you'll also gain an RCA video output, making it easy to add an additional video output if you want.

Some of these converters will allow simultaneous charging and output, so you can leave it plugged in and not worry about additional charging cables.

If you have a compatible data service, you can run the device tethered and get streaming music and movies, gps and calling, all on the go.