Sure, this first photo is what I carry in the trunk - the spare MSD box and a strap. I said earlier it was a velcro strap, but I didn't remember that correctly as it's been a number of years since I've used it. I stuck some hard foam pieces I had in my junk drawer to serve as spacers to the bottom of the MSD box.
The photo below shows it mounted to the original MSD box, which is under the dash below the glove box. The original box is rubber mounted to reduce vibration and provides the space for the strap. Not much to this really...
