Here's a couple of idea I thought up for securing models to display base for transportation to shows etc. Never actually done it so can't confirm it works.
First shows a metal rod tucked into the wheels - ie front pair and rear pair. The rod will pin down the wheels thus securing model to base with a legnth wire that will twist together on the underside of the base. Remember that you will need to drill a hole for each end of the wire.
Second shows a similar princple using a length of thin metal rod or thick wire pinning down each wheel
