No CD Changer display

Either the unit's motor is bad or the mechanical parts are dirty not allowing the unit to change CD's or load them.

I dont remember if that year had a theft lock system or not, but I am looking into it. disconnect the negative battery cable for ten minutes and that should get you back to where you can enter the unlock code again and use the radio.

A couple of different possibilities here but this is a typical problem when it comes to the MB cd changers. Before ruling the cd changer bad, check the spring settings on the sides of the changer. Make sure they are in the 'H' position since it sits in the glovebox. The Mercedes cd changers don't have a reset button. 95% of the time its the cd changer that is bad when this scenario happens. Its caused by a linkage that gets knocked out of place internally of the cd changer. Also try not to use burned or homemade cd's as they can also cause the cd changer not to read the discs anymore.If your cd changer is brand new or a factory rebuild then the dealer should change it out no problem since MB cd changers are known for this problem. Also the version coding needs to done to configure the D2B fiber optic ring properly.

check all of your connections going into it may be corroded at electrical connections or the cd may need replaced

Did you check the fuses? Maybe one is blown.

The fault is actually inside the CD changer, when one disc is selected the changer moves the gearing inside to slot from one CD to the other.
While this operation is happening the selection arm jams !!
Then giving an error at the radio display..

To fix the problem, disconnect the CD changer from the trunk of the car,
take off the top plastic slide cover,
with a small screwdriver slowly move the gearing so that the CD disc holder will move back to the load - unload position.

Pop out the CD holder.

Replace unit, reconnect the optic and power lead, switch on radio and the unit will work again,

grease the moving parts with light lubricant

Good Luck

the unit at front with the ac controls is just a remote control unit , the radio is in your trunk left side
you have to remove the carpet and you will find a free 13 pin plug , that is the cd changer connector
it is the same in all taurus and sable from 1996 to 2007
the radio looks like this picture

this is the cd changer

Likely have a Monsoon radio system in your 2000 Beetle. The CD changer is controlled by your radio, and not any CD changer will connect to the outlet in your trunk. You can either find a CD changer on eBay (or elsewhere, or swap out your radio for a radio from a newer VW Beetle that has a CD player installed instead of the cassette. Can also find those on eBay.

you will have to purchase new cd changer or go to an after-market cd changer that has an rf transmitter that plays thru your radio, i had mine checked at mercedes dealership and they told me it would cost $800.00 plus to replace it and an aftermarket one would cost about $200.00 to $250.00 to put in a new one.