I don't have my car yet so I don't have a definitive answer (owner's manual doesn't show a way) but since I ordered mine with BLIS, I'm wondering what bothers you about it such that you want to disable it. Annoyance? False readings?
I don't really need it for normal city driving because there are plenty of cars around me and it gets distracting having the bright orange lights blink all the time. Its only useful for me on the motorway so I would prefer the option to turn it on rather than turn it off for each journey.