Your local airfield has just done you a favour. If you don't have airside insurance and you write off a £50k aircraft, and even worse the occupants, then unless you have a lot of loose change then the 3rd Party's estate will take your house or you will go to jail.
I really have to smile when I read this uniquely European point of view. Nobody worries about this nonsense in the US, nobody knows what "airside" means, and everybody drives on the ramp. In fact at my airport the
only way I can get to/from my aircraft and hangar is by driving a car - you can't exit through the gate without a car to trip the inductive sensor and open the automatic gate. There is no pedestrian access.
I'm sure about once every fifty years it causes a problem for somebody, somewhere although I've never heard of it. My risk mitigation technique is to not hit anything while driving the quarter mile between hangar and gate. Aircraft have right of way on the ramp and that's the only rule required to prevent problems.