Hello there! 2004 BMW Z4, 3.0 (E85)
w/ S677 HiFi System Professional DSP
After extensive research for a month, I have finally been able to install the Joying Android HU on my car with stock speakers, amp, harness, etc. Maybe I will call it a plug-and-play setup with a twist - you will have to attach the cables and modules to the Head unit beforehand. I don't want fellow enthusiasts to go through the pain and remorse I went through. That's why I have created this installation guide. There are too many people out there who will tell you that this cannot be done without replacing your all speakers and amp. But trust me, even an electrical newbie like me was able to install this without any shocks or heat burns.
The guide is a long, well-detailed pdf with images and links for further support. I will post the equipment checklist here and link the pdf. There was supposedly a similar set of instructions someone made a long time ago which was lost and the OP was unreachable -
viewtopic.php?t=122211
However, my link will remain online as it is hosted here, as well as on public Facebook groups. Someone else with more experience can post links here as I am not sure if the forum allows linking to social media.
I will reiterate - this is an easy installation of any Android HU (with USB input) on E85/86 HiFi Pro DSP with working audio and steering wheel controls with stock speakers and AMP. So let's get into it -
Make sure you have a factory-installed amp with DSP
- S677 HiFi System Professional DSP
https://www.rubmw.ru/vincode/en/
- Connects2 CTSBM004.2 interface for steering wheel controls – amazon US link
- Head unit patch lead for Connects2 interface – generic (key 1, key 2, gnd)
- Resler USB I-BUS module incl. cable
- I-BUS App with DSP license purchased
- Wire connectors (butt, soldering, etc), crimp/strip tool, electric tape, etc
- Aftermarket Radio Antenna Adapter Plug (optional, if you want radio function)
- I used Joying 10.1 single din android 10 unit – link
- Dash Kit – link and M5 screw | do not use this alternative, as it is very flimsy, and the unit slips through it.
Installation manual
Print Edition
Working video.
https://youtu.be/FP2yhgPt6Sg?si=LGHUtzQsg7ojH_Gq
I had to replace the song with a non-copyright song on YouTube. I really love the Backstreet Boys

Feel free to reach out in case of any queries or feedback on the manual.
happy driving!