That would be irritating. What kind of stereo is it? If you can find the brand and model number, you can probably look up the manual online.
This is a great idea. I can't remember the brand name off the top of my head, but I'll write it down next time I'm in the car. This stereo has been getting on my nerves so bad that I was just about desperate enough to take it to a stereo shop and pay them to fix it for me! I'll see if I can find the manual online, first.