It was £240, John (so, as I said in my previous post, stupidly expensive - but as a proportion of the overall cost of the new car, not that great, I guess). One of the reasons I bit the bullet and forked out for it, rather than taking the Pure Highway is that it is mounted behind the R-Link console - there are no trailing wires or separate head unit - and you use the controls on the steering wheel stalk to control it. The only visible cue that it's fitted is the small DAB aerial mounted on the windscreen.
Tony