I'm not sure but I think BMW changers are made by Alpine (at least some were). Do you know if yours is? Also is it MBus or AiNet?

I have built a proto MBus changer interface and have a lot of the software protocol figured - I just need some time to finish off the empeg software to make it completely useable. I'm building harnesses for people at the moment but once that finishes, the changer control begins (will I'll begin the end considering I have half done now ).