Depends on he airfields you intend to go airside on.
Not many people appreciate that general motor cover does not cover airside activity. My airfield has a big sign at the gate advising drivers to check with their insurer before going airside.
Even modest airfields could represent a big liability.
Clipping the tip of a Citation wing could cost more than £250k by the time you have added in all the costs other than inspection and repair such a consequential loss, aircraft substitution etc. If you are under insured then its a personal liability and it would take more than the disposal of the Eurofox to pay for it.
Insurance is one of the costs we hate having to pay as unless its called on it seems a waste of money.
The biggest waste of money though is being underinsured.
I would suggest two things, insure for about the same level as the aircraft is for third party damage usually in the £3m category if you are a frequent airfield driver or decide not to go onto airfields.
It can be a bit inconvenient lugging stuff to the aircraft in a couple of trips but it gives peace of mind.