Here's the situation:

Miss A and Mr B have lived together for around 12 years.

A couple of years ago they borrowed £5k from Miss A's parents to buy a car.
This was a verbal agreement; none of the money has been paid back. This is a
major bone of contention - the parents want their money. It is unknown
whether there is a receipt for the car.

The car is registered in Mr B's nameand was used by Mr B as the family car.
Miss A does not drive.

Recently the relationship between Miss A and Mr B broke down, to the extent
that Mr B no longer lives with Miss A. There is a huge amount of bad feeling
on both sides, and for the purposes of this post let's assume a
reconciliation won't happen.

Mr B has said he is going to keep the car. Miss A's parents want it back as
part payment for the debt due. The car is at Miss A's house and she holds
the V5 and one of the two sets of keys.


Who owns the vehicle?
If Miss A's parents can prove they paid the money for it - say by showing a
bank withdrawal for the £5k at the time the car was bought - can they claim
ownership?
Can the vehicle's registered keeper be re-assigned to be either Miss A or
Miss A's parents - none of whom drive - without the consent of Mr B?

None of the family are the kind of people to sit down and discuss things
rationally.