I may be wrong, but I think you are going to have a hard time finding a third party unit that will look good when installed because of the factory bezel.

My Crutchfield catalog doesn't list a kit for any late model Volvo. The website indicates they have over a hundred units that will *fit* (they say it's a standard Euro-DIN form factor), but looking at a few of the offerings, I don't know how you could make them look nice without either having a custom bezel made, or finding some way to cut out the existing bezel.

If the only issue is having a CD changer, why not get the factory optional 10-disk changer that goes under the floor of the cargo compartment--the factory head unit already has controls for the changer built-in and the wiring harness is already installed...

If you want a less costly package than OEM, it will probably be cheaper to removed the existing unit and replace it with a good aftermarket system. A site like Crutchfields should be able to give you ideas for options. Once you decide on which brand/model you want, you can then buy them cheapest via Ebay (new) and local stereo shops can probably install the system if you'ld rather not do it.