Or is it simply a case of...
You know you're right. I'm all jealous as hell about your fuel bills and proposed higher tax etc.
Actually the point I was making was that you were advocating that the Airshow should have gone ahead, as your 4x4 would have been okay dokey. [hence I'm alright Jack]
As regards Insurance, at the time of the "hypothetical" towing the car park would be classed as an "other public place" and the Road Traffic Act requirement for Insurance would apply. Whether the punter tied the rope or not, you as the "tower" could/would be held responsible for any damage caused.
Cheers
Stew