01 wolfsburg cd ready?

It's located in the trunk... Not sure exactly where in a Jetta, but in the Golf's the location is left hand side of the trunk, behind a little compartment door (two twist open latches). There you would find the mounting braket and the cable.

I've got the VW 6 disk changer, I think Panasonic changers are also compatible.

There is also a single slot CD player you can add-in on the dash. I have both in my car (a 1999.5 Golf TDI) and it's a pretty sweet setup. Very easy to install it yourself, but you need the radio removal tools to install the single slot CD player (the single slot player allows you to select between changer control or single CD control with a "select" button, the one in use will illuminate thru an LED). To install both you have to changer an electrical connector at the back of the radio... either the CD changer or the CD player would normally be able to plug in, all you have to do is unclip one of the two blank ones and clip in the wires for the player and you can have both running thru the headunit (looks like it can handle one more audio accessory as there is that mysterious third blank connector).

the changer is optional and in the trunk behind a panel. if it doesn't have it, it's pre-wired (all late model VWs except the Eurovan were pre wired for the changer).