Hello people I know you guys wont take long to amswer my this question. I had Audi factory fitted stereo in my car including the CD changer which was the concert model I swaped it with my alpine MP3 head Unit which I had in mine BMW , Well the problem is I nknow it's staright swap basically only the problem I am facing now is whenever I do the setting on my head unit after switching the car off , I loose all the memory on my head unit can any one help me with this its really annoyieng at the moment . Do we loose the display as well when we change head unit to after market one it's gone blank now . Last thing I am not getting any sound on the rear speakers only the fron one's . Please help me people .