Unusual motor insurance clause

[fredpuli47]

What mischief is this restrictive clause , now found in motor insurance policies ,aimed at preventing?

" This policy does not cover use to secure the release of a motor vehicle, other than the vehicle identified above by its registration mark, which has been seized by , or on behalf of, any government or public authority"

[Ethel]

Mr C's car is impounded for no tax.

Not a problem, he thinks. My friend Mr X is allowed to drive 'any other vehicle with the owner's permission' on his insurance -he can say he was driving and it was insured on his policy and I'll get my car back.

Oh no he can't! This clause specifically prevents retrieval of a vehicle other than the one it is insured for.

[Ethel]

Obviously, in my scenario Mr C has no insurance either.