Spare wheel theft prevention

[Tonyash]

Hello, any suggestions out there for securing the spare wheel against theft?  I suppose any determined thief would overcome most locking methods but any is better than none. 
Thanks

[Trevor]

My Mk2 had a spare wheel anti theft device fitted by Citroen after I had mine nicked
It was a plate in the boot floor with a long bolt that went through to another plate that was fitted to the spare, so you had to open the back door to release it first.
It worked ok but left a bolt head sticking up in the boot area which was most unsightley.