Must be a great honour to get your car in nationwide print.
It's not really. 99% of the benefit is to the magazine.
For nothing more than reimbursing the owner for the petrol he uses to get to wherever they want you to go & an eight quid pub lunch they get a the free employee & the use of his car for the day to take free photos to sell their magazines.
If they had to rent the cars, particularly older 'mint' models, they would have to pay hundreds (or more) per day.
If you are selling your car it can give great exposure, otherwise they are taking you for a mug, IMO.