Totally agree with the above, bloody stupid and dangerous. According to the chaps over at Motortalk.de, this "feature" is available if you have the advanced phone prep (which we don't have in the UK - we have standard and optional comfort).
Also, anyone noticed that it actually takes quite a long time for the system to hang up a call and revert back to whatever music source was playing ? In the scirocco, it was pretty immediate (say about a second or so) after pressing the end call button, whereas in my GTD, it takes about 7-10 seconds for it to hang up and revert back to music.