When insurance companys allow you to drive any car this is what they mean :

Your insured to drive the car on the road but

A , You must have the owners consent before hand

B , Whilst driving your covered by the minium amount of insurance required by law and that is THIRD PARTY ONLY !
C , If your involved in an accident with another vehicle and its your fault , they can claim on your insurance , if you crash the car and no other car is involved then you alone have to pay for the repairs .
D , You are not covered for theft of any kind , which means if you stop at the shops and some little scrote fucks off in your mates Cossie you better have a healthy bank balance as your insurance wont pay out .
E , As soon as you stop driving and park up your no longer insured on the car until your start driving it again .

It also doesnt matter if the car has current insurance or not because whilst on the Queens highway the car is insured through you