I have installed a ULF bluetooth system in my 2001 X5 with nav and no DSP. I have also installed the ELK 800 audio amplifer as in researching the retrofit without DSP it is necessary to get the volume to an acceptable level, I tried it without and was too hard to hear. The problem with this installation is that when you are in a call and you turn off the igniton, it kills the ELK amp while the ULF holds the active call, therefore audio is lost. I am wondering if there is 12v output on the either the audio system amplifer or radio module that retains power during an active call through the ULF and then cuts it when the call ends. Any insight on this would be greatly appreciated.