Best Buy installed new stereo in my 1996 Z3 - Now my stereo stops playing when I put the drivers side window down. My car recently started blowing a fuse. Help...it's been almost 4 years since I had the stereo installed and the problem has gotten worse.

:o( you're going to have to pull the radio out to see what they did. They probably added a wire to an inappropriate circuit to power the new radio or amp. I will paste your factory wiring colors below. If you now have an extra wire, that is the likely culprit. Trace it to see where they hooked it in. If it isn't going to the the fuse box and using an extra slot, make it so by connecting it to the cold side of the fuse and put an approprite size fuse in. To determine the fuse size to use, you can compare the wire gage to other cold side wires and use a fuse the same size as you see being used for similar gage wires. Let me know if you have more questions.

1996 BMW Z3 Car Stereo Installation Diagram
Car Radio Battery Constant 12v+ Wire: Red/White
Car Radio Accessory Switched 12v+ Wire: Violet/White
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Gray/Red
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: White
Car Stereo Amp Trigger Wire: White
Car Stereo Amplifier Location: Passenger Kick Panel
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Yellow/Red
Left Front Speaker Negative Wire (-): Yellow/Brown
Right Front Speaker Positive Wire (+): Brown/Black
Right Front Speaker Negative Wire (-): Blue/Brown
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Blue/Black
Left Rear Speaker Negative Wire (-): Yellow/Brown
Right Rear Speaker Positive Wire (+): Blue/Violet
Right Rear Speaker Negative Wire (-): Blue/Brown