You can get ones that fit to a towbar, but that means you have to fit a towbar. Someone on this forum posted a while back about ones that fits to the boot rails but I can't find the post with my first couple of searches. Maybe have a go yourself?
Sorry.
When requesting help of a technical nature, please give as much detail of the fault as possible along with details of exact model, engine size & type, gearbox, year, mileage, and any relevant work carried out to try to solve the problem to help us help you.
Better still, put the details in your signature.