You don't need to buy a new radio to add a CD changer to your vehicle.
All you need to do is get an universal add-on CD changer (aka, an FM modulated changer).
FM modulated means it will send a signal through the antenna wire to the radio so the radio doesn't need any special inputs to accept the CD changer. You just need an FM radio and then set it to the frequency for the player (the player will have an adjustable frequency to avoid interference from local radio stations).
If you're handy enough, you could probably install it yourself, but if you've never done anything like that, then I'd recommend having it installed for you.
A great benefit of having an FM modulated changer is that it can be used with any car radio with an FM receiver and an antenna input. Also, you can have it removed and installed into a new vehicle if you buy a different vehicle.
So, if your factory radio does die out on you, you could get any brand radio to replace it. Most changers that are tied into the radio are made to work with just that particular brand radio.
Crutchfield sells them, and will give you an instruction booklet on how to install it into your vehicle. Here's a link to their universal changers: http://www.crutchfield.com/App/Product/Group/ProductMenu.aspx?g=610&tp=133 you can either call them, or order online. If you've never ordered from them before, give them the following referral code to save $20 -- p6v84-8jd02-ywzu9) Or you can go to a local electronics store or stereo shop and see what they have and how much they charge to install it for you.