Hey guys, I would like to add Android Auto / Apple Carplay to my W204 from 2011 - The VIN Decoder mentions it has 523 AUDIO 20
I've highlighted below with a RED SQUARE my Radio UI and Unit - I'm confused which NTG my car has.

My radio unit looks NTG 4.5 (without the SD Card):



And my radio UI looks NTG 4.0:

I'm not 100% but you might have the SD card slot in your armrest center console. If so I think you're 4.0

This is what I have in the armrest:

• USB A
• Thing that looks like an AUX but isn't one (Not sure what it is)

Image:

I'm not sure either then. I would contact the seller they will know I would think.

Audio 20 comes with the console without the SD card slot. COMAND has the SD card slot version of the console. With Audio 20 you should have the Becker navigation box in your glove box.
You can gain access to Engineering Mode on the console. Hold the “End call” and “1” and “#” keys simultaneously for approx 10 seconds. There’s an option in there to show the hardware version. Tread carefully as changing options could cause problems, Good luck.

NTG 4.5 earlier models has yellowish UI as the newer models has Silver UI. But both are NTG4.5/7

I don't have the Becker navigation box in the glove box unfortunetely (It's super easy to upgrade to Android Auto with it).
I'll try to fetch the Hardware Version from the Engineering Menu.

I'm also confused what my NTG is, I have exact same situation like you. I also have Becker nav in glove box.
Did you manage to find out what NTG 100% is yours?