I have, for a while now, heard that leaving CDs in cars where they get cold at night and heat up during the day isn't good for them, and leads to data loss. I was curious at to how this can be tested, and if anyone has ever experienced this themselves, and what type of CD it was that you have experienced it with.
I'm sure it's not good for them, but I don't think I've ever had a CD go bad from leaving it in the car. (I did have one crack for "no apparent reason", once.)
I've had several heat-warped (polystyrene) jewel cases, but the (polycarbonate) CDs have been OK.
The best solution is probably to make a copy and "archive" the original. I don't go to that much trouble, but whenever I copy a CD, I make an extra archive/backup copy. (I can't use the copies in my car because my factory Honda CD player has trouble with burned CDs.)
A few years ago I worked with a guy that was a part-time DJ. When he had a gig, he would bring his vinyl records in to work. At first, I assumed he was bring them in to plan his gig. Then, I remembered what happens to records in a hot car!
P.S.
Oh, I forgot.. freezing CDs makes them sound better! (http://www.answerbag.com/q_view/104847)[/u][/color].
My experience from leaving the cds in a car is limited to rewritable cds, some which have data (mp3) and some normal redbook audio. Only one cd has been destroyed during 5 years with only handful of rewrites, and I suspect the fault was at the medium itself, not the conditions. this samsung branded cd-rw was the first and so far the only cd-rw of its brand purely in in-car use, but couple other samsung cd-rws become unusable in normal office conditions in only two years of normal use and storage. other brands used, such as verbatim, are as good as new even in incar usage, only minor scratches from the dirty slot mechanism.
cds currently in use are approximately 4 years old, some little older some younger. I'm waiting for the moment when I need to refresh my mediums
And yes, the conditions here aren't very great, during winters the cars temperatures rise from -20 degrees Celsius to 16 (I like my car warm ) during the travels every day and cools down again.
I have had one CD in my various cars ever since 1994 (Korn's self-titled album). It started off in my 1991 Grand Am with my older CD Walkman and cassette tape adapter, 1995 Ford F-150 with the same previous setup except a newer Walkman, 1998 Ford Escort (had an in-dash CD player which I later upgraded to a Kenwood model), and now my 2009 Honda Civic. The CD has remained in its original jewel case for that whole time period in the glove compartments of each car. My 1998 Ford Escort went with me to Cincinnati, OH where it experienced temperatures below freezing. I live in southern New Mexico where the summers get above 100 (which means that the temperature in the car is about 110-120). That CD is still fine. I have had to run it through a SkipDr. about 5 times but the scratches were caused by years of putting the CD in and out of various CD players. The jewel case and artwork are still in tact as well. No warping or anything like that.
I am sure CDs can become damaged if they sit out in direct sunlight for years on end. However, you shouldn't have any issues if the CDs are properly stored in the car (ie the glove compartment, middle dash, trunk, under the seats, etc.).