Swapping Number Plates

Does anyone know a sensible (and tested) way to swap between number plates on a caravan, without having to keep gluing the plates on with sticky pads and then peel them off again? Sometimes I tow with my car and sometimes with my partner's car, so I have to change the plates over from time to time.

Halfords sell a "number plate frame" which I suppose I could stick to the caravan to allow me to swap the plates more easily. Has anyone used something like that? The back of the frame is mostly holes, so I'm not sure how well I could stick it to the caravan and I do not want to screw it on.