Theft-proofing a convertible with no steering lock

When it comes to theft, overkill is the best policy, then the dumb B*stards will walk away and hit elsewhere. My whole street is full of flood lights, security cameras and many retired people with nothing better to do than spy on everything and call the cops for every person or vehicle they don't recognize........ Nothing gets messed with here........... But they are sticklers to every rule and ordinance.