PinkCosmos
nadateturbe
It's not relevant to the issue but I'm insured fully comp to drive my husbands car and vice versa.
Yes. This is what I thought the insurance covered.
I thought that if you were insured full comp, you could drive any other car.
Pardon my ignorance if I am wrong.
If they have only one car, then only one of them can be the 'main policyholder', the other is just a named driver on the policy. The main policyholder can usually drive any other car on a third party cover - but not always, especially with a cheap insurance policy.
Third party means they are legal on the road but if there's an accident the insurance will only pay out for the other person involved and their vehicle, not yours. Additionally, if the wife is the named driver on their car insurance then she won't be covered to drive your car. Either way, the insurance is a problem and you're likely to lose out if there's an accident.
As others have said, if you want to keep the car available for you to use then suggest the neighbour takes out temporary insurance each time they use the car - and make sure you see their policy as proof!
Otherwise, declare the car off-road (SORN), provided that you can keep it on your property and not on the road (!) - it's very easy to do and you can do it online. Then you will save the cost of road tax and it's not available for her to use. If you decide to make the car off-road, do it before the start of a new month as you have to pay for a whole month's tax if the car is not off-road before the 1st of the month.