I have a 2012 A3 Sportback. I would like to install a dashcam. I notice that the 12volt outlets are on all the time. Is there a work around to have the outlet turn off when the ignition goes off? I have also seen some cams that replace the housing on your rearview mirror. These seemed kind of dogy to me, has anyone had any success with these?, Any advice and ideas are greatly appreciated...Thank you