I am thinking about using a 2.5" HDD in a external enclosure loaded with all my mp3s and connecting it to my car stereo via USB. I can't have the HDD on all the time as it will drain the battery so my concern is will the life of the HDD shorten considerably if it's constantly turned on and off whenever the car is started or turned off? I can't seem to find a power adapter of some sort to softly turn off the HDD.
