yes- always have one, even if it is locked in the car, since my office has a "security policy of no cameras on property" - as if trade secrets of our software can be had by taking a snap shot of the building or landscaping or co-workers.(*dumb but i dont make the rules)
camera is there in case -- such as a great night scene, stormy sky, or a car fire or such, on the way home.
usage - infrequently, but acts as insurance that i wont miss it (have captured things over the years) so it is there daily.