> the snatch-and-grab attractiveness of it

I think that's a valid concern whether it's in the car or in your had, given that it appears to be an item of interest to thieves and teens. (:->)

I have a friend who uses a padded diaper bag for just this reason. It stores all his stuff, is padded and water proof, and nobody ever steals soiled diapers (which it appears to contain).