My mom is just the sort of tech-noob to do a lot of dumb things, but I don't think I've ever seen her leave behind the iPod (the one I recently replaced for her with the CM7 Nook Color) in the car when she got out--sounds like an anecdotal experience on both sides of this issue. Regardless, perhaps the tablet bay in the car could have a slide-up cover to hide it when the car's been turned off for half a minute... then slides open when you unlock the car door (so it's ready and open by the time you sit down). My Honda Del Sol has a slide-cover to protect the radio (since it's got a removable hard top), except that mine is not motorized and automatic.