I just bought an older car with an after market Sony CDX-GT06 car stereo and noticed that whenever I leave the faceplate in it drains my car battery to where I can't start my car and that after only 20 min. I am thinking the original owner wired it directly to the battery, the battery is too old (It's 4 years old and I just installed a new alternator), or I am doing something wrong (after playing a cd I just turn off the car and don't necessarily push the 'off' button). Any help is appreciated. Thanks!