Been an electronics and audio guy for about 15 years but this problem has me stumped so I thought I'd reach out to you all for some ideas. I have a 2004 Infiniti G35 that is pre-bluetooth connectivity and I wanted to get it to have at the very least bluetooth streaming music from my iphone. What I did was buy a cassette adapter and then connect the 3.5mm cable coming out of the cassette adapter into a bluetooth adapter, which would connect the my phone. It was all working fine but I took my car to get some minor electronics issues fixed and the tech suggested that i have an RCA soldered directly onto the back of the PCB for the stereo so that it would be a cleaner sound. I said fine, cause it was only like $20 extra. Anyway, I get the car back and when I plug my phone directly into the cable they soldered for me it works great. Sounds awesome. now here is the kicker... when i plug that cable into my bluetooth adapter and try to play music through the phone it sounds all garbled. When i take the bluetooth adapter and use it with another stereo system (like my home stereo) it works fine. I can't figure out what to do... I thought it may be an issue with the 3.5mm jack not connecting with the inside of the bluetooth adapter so I got an extension cord to see if it was the connection. Same garbled sound. I am out of ideas. any thoughts?