I recall a debate on another Rover/MG forum (!) a while back when someone was asking if it would be possible to have the cruise permanently available. I also recall that it got a little heated!
Duncan wrote:I think the off switch is so there's no danger of you accidentally knocking the steering wheel switches and switching the system on. However I know of other brands where you can leave it permanently switched on. Probably the same reasoning in the handbook warning.
This, I think, was cited as the reasoning against it. Someone said something along the lines of the steering wheel switches might be knocked when cornering. Logically though, they might also be knocked after you have engaged the system, so it shouldn't really matter! Also, as Duncan rightly says, other manufacturers don't use a separate on/off control, for example our Ssangyong Rexton. In that, you have three options for initial speed setting (from a fresh ignition on scenario), which are push up, push down, or push away. To switch it off (physically, as opposed to braking etc), you pull it towards you. After an initial speed has been selected, pushing up speeds the car up, pushing down slows it down, and (assuming that it has had one disengagement) pushing away is resume. Nice and simple, and I've never yet accidentally engaged it!