"Keep in mind that anything unsecured (and heavy) in your vehicle will become a missile in the event of an accident, or even evasive maneuvering. Better safe than sorry."
If I planned on leaving it in I would probable secure it.
By the way - I decided to mount the Monitor stand on a larger Aluminum Plate makes it much more stable.
It's apx 10" x 14".
Most likely I will be selling it before long as I really never use it now days
Good point though even on the floor if the Van was rolling over or whatever - it could be a problem!
If I decide to keep it I will either secure the plate or just mount the haed somewhere like the side of the Passenger seat base.