<sigh>You have a very nice problem. I'd like to have a car that could toss the empeg of its harness...

While this might not be a good solution from an aesthetic point of view, a small catch that rotates 90 degrees to lock the empeg in place would be very functional. With a nice stainless screw holding it to the dash, and a some custom dremel work on a piece of nylon or other black plastic, you could probably get a good organic shape that would look pretty decent. This would have the advantage of not having to mess with the somewhat clockwork lock levers on the precious empeg. Levers like this are often used to keep things from flying about on heeling boats. Just a thought.

-Zeke