Is there a master LWNT for Vauxhalls? How is this problem overcome in the trade?
Most main dealers should have a master set of locking wheel nut keys. They use them when cars come in for service or tyres and the customer either hasn't left or the mechanics can't find the locking wheel nut key. It's usually a case of trying similar ones until they find the one that fits snugly. There is a letter stamped on the end of the key, which will identify it, and from this the correct one can be purchased if you haven't got the code.
If you intend to bin them (as I have), and can't get the car to the garage, I would take a photo of the pattern of the locking wheel nut, visit your friendly Vauxhall garage, and depending on how well you know your them, see if you can borrow the keys that are possibles. Take four ordinary bolts with you, and remove the bolts replacing them with the ordinary ones, before returning the master key.
It's better however if you can go in the car and do it on their forecourt, but if they know you, then they may help you out by lending you them, but it may depend on how much you've spend over the counter in the past!
I've done this before when I have bought cars without a locking wheel nut key, before finding out the hard way at the roadside with a flat tyre.......