Two little deterents to make jerks think twice before messing with your interior with the top down are old biker classics.........#1 Get an empty gun holster and strap it somewhere in plain sight like the rearview mirror. #2 Put a sticker on your windshield that says " IF YOU VALUE YOUR LIFE AS MUCH AS I VALUE THIS CAR DONT F@#K WITH IT". You would be surprised how effective these things are......