OK thanks, I was talking to a merc s class appx 5 years ago, he was an executive hire, but,his merc had a non optional version & he did not like it at all for london driving, other cars coming over the white lines, heavy goods have part of their bodies over them, he said it would be good if it was optional, to me it sounds common sense to have it as an option
I suppose there is drving a car & fighting your way through london with one