Hello
I've just bought a single CD player for my Mk IV Golf, which looks like this:

My Golf currently has the standard VW Golf stereo with a slot above it, I guess for the CD player to go.
So I managed to ease the pocket/slot above my radio cassette out, and found the socket on the back of the Radio for the CD player, the CD player works and the lights on the CD player illuminate, but, as I slide the CD player back into the slot, the power cuts out.
Firstly, is the CD meant to be on the top of the radio casette, or should the radio/cassette be in the slot above, and sit on top of the CD Player?
Secondly, is there anything else in the slot that should be removed before sliding the CD player into the dash? Is there a knack as to where the wire on the back of the CD player should go as I'm sliding it back in?
Any advise would be greatly appreciated!
Thanks.