I installed my wireless carplay adapter for my NBT (which was also a retrofit, so i wasn't even completely sure it would work installing an adapter into an adapter)
worked perfectly. audio quality is perfect, sounds no different than listening to the NBT headunit.. better than bluetooth i think.
installation was a bit complicated because of the fact that i already had extra hardware in the dash (quadlock connector for NBT retrofit, NBT emulator, etc.) but we managed to get all the cabling tucked in to the side, and we relocated the NBT emulator as well as installed the carplay adapter up under the glovebox.
overall installation isn't really any more difficult than replacing a car stereo. the instructions are minimal, but clear enough.
this unit itself has a lot of options that you can configure, change the name of the bluetooth pairing, an EQ that works, other audio settings, carplay and android settings (i won't test android because i don't use android) really really simple and straight forward.
happy to answer questions and/or test some things out for people.