I have a RADAR key... watch out for busy bodies - I have been challenged twice now, once by a member of the public and once by a toilet attendant, neither of whom believed I should be allowed to use the facilities - I only use the key if there is a queue (or I really need privacy - if you know what I mean)... but some people really can't grasp the concept of a person outside the confines of a wheelchair using the disabled toilets!
On both occasions I explained I have Crohn's (blank expressions on their faces), so instead I offered a choice - leave me alone to use the facility or I would make a deposit on their shoes... they seemed to think I was rude...
he he he!