Just a word about the dealers. Following a spate of thefts from the forecourts of local dealers, they're no longer providing codes remotely and the stereo needs to be fitted in a car before they'll do it. Also, all the serial numbers of the stolen units are logged with VW, so if you try and get a code for a stolen one then it might get awkward. This also applies to Ebay sellers who are simply accessing the VW database to retrieve codes from the system.
So much better to buy one with a code supplied, unless you know for sure that it's above board.