I did receive the module today. Unfortunately the pin descriptions do not fully match to what I can see on my bench unit. My Car unit does not have any pin descriptions on the silkscreen at all.
Bench Unit Bluetooth Module pin descriptions: x -BLED ---RST ---SDA ---SCL ---GND ---VDD ---MIC- ---MIC+ ---SGND ---LOUT ---ROUT x--PIO10
The first and last pin do not seem to be connected.
And here the pin descriptions on Aliexpress module.
Aliexpress module pin descriptions: ---RST ---RX ---TX ---GND ---5V ---AGND ---NC ---GND ---CTS ---RTS
Basically the first pins (RST, SDA/SCL/GND/5V) might match but the second part of my bench unit WQ_BC5 seems to be some audio interface (MIC-, MIC+, SGND, LOUT, ROUT) while the Aliexpress module provides some potential serial interface (GNC, CTS, RTS).
I guess I will have to check some schmatics before. Perhaps my car unit is wired differently too.
Looks odd, I wonder if it's an error in printing on the board. AGND is usually audio ground, but I don't see any [mic] or L, R.