I've been thinking about that as well, even though I don't have a convertible. When I go surfing or mountain biking, I have to leave the truck unattended for long periods of time, and I don't want to leave my empeg in view in the dash. In my case, I don't need a locking box, but I do want something I can slide the empeg into that will protect it from all the springs and pokey bits under the seat. With my seat, I can actually slide the empeg under the seat from the side. With a box that keeps it from being pulled out the front, closing and locking the door becomes the lock for the box. I have my doubts you could do that in a convertible, though. The price you pay, eh?