Shuffling through your CD's on the move has never been a good idea. Not only is a safety issue but there is always a chance that your Shania Twain CD will tumble into the passenger foot well. How did that get there? Last time I lend the car to my mum. A Car CD changer makes all this go away and provides you with endless music from your CD's and, with some, CD-R and CD-R/RW not to mention a nice bit of ICE in your motor. Check for the quality of the Laser pickup and that the anti vibration mechanism employs suitable dampers for that non-skip experience. Optical digital output ads another layer of quality output but be wary of the title memory as it might give your passengers another 'Shania' surprise.
