Re: Insurance and driving other cars
I used to be an insurance underwriter for an insurance company (tedious job I know) but basically the third party cover driving someone elses car is there to be used as a very temporary measure.
There are certain conditions to it though
1. the other vehicle must be insured (this is to stop young drivers insuring a 1.0 litre AX and driving a Scooby to avoid paying thousands in insurance)
2. the other vehicle must be used by express consent (i.e. you cant nick a car, crash it and claim your insured)
The whole driving other cars using third party only cover was originally suggested to be there in case of emergencies (i.e. taking people to hospital, or if the main driver fell ill on a journey etc) and should only really be used as such.
The cynics may suggest that it is a way of insurance companies squeezing more premium by having to add additional drivers. Most companies now will charge approx £20 - £30 to add a driver (the premium will be more if the additional driver is younger than the main driver) and most, Direct Line included, will add the driver for the remainder of the policy rather than adding the driver for a week.
Now, bearing in mind that you have contacted the insurance company on a few occasions to clarify the situation and at least twice you have been advised that it should be used for 'emergencies' only, you would be best adhering to their advice. Mainly because if anything were to happen, you will have been recorded during the telephone conversation and they can use those recordings when deciding to pay a claim.
However should something happen (and I am not suggesting anyone commit insurance fraud!!!), the insurance company would only prevent pay out in the event that at the time of the accident, it was not an emergency and proving that could be tricky (especially as the main driver fell very ill, very quickly ahem)
I am also astounded that your mates insurance company does not allow additional drivers, unless the vehicle is in a particular group eg a high powered sports car, that they impose restrictions on say the minumum age of additional drivers is 30.