I find that when I insert a CD, it takes at least two tries to ever get it to recognize the disc... unless I give the dashboard above the player a solid smack. It's too early to reach the "smacking" phase in this car, so I'm disappointed. Any suggestions or is it time for a trip back to the dealership?
It looks as though you've had the car about 3 years. Are you still under any warranty? If so, then it is off to the dealer. Otherwise, get a new radio -- one that let's you connect your iPod directly. Then you won't use the CD player unless a friend hands you one.
Also the changer may have problems with CD-Roms or dirty disks. So try a virgin commercial CD. If the paler won't accept that, then there is something wrong with it.
If the problem is with commercially stamped discs then get a new radio. If the problem is with CD-R or CD-RW discs, then try a different brand of discs. Some players have trouble reading some brands of discs.