I haven't looked at this thread for a few weeks, but as soon as Radar keys were mentioned, I suspected that it would turn into a discussion about the rights or wrongs of using them!
I have a Radar key on my keyring at all times, mainly because I occasionally take my elderly disabled mother out on shopping trips etc. (She has her own, but cannot always find it when needed).
When I'm out in my campervan I don't need public toilets on a daily basis because I have my own facilities on board. When I need to top up with water, or empty the cassette, I use the standard public toilets when I find them and not the Radar ones. I don't think there's a need to use Radar toilets for cassette emptying.
However, if I'm out and about in my car and the only toilets available are Radar ones, then I would use my key, making sure that I'm not "inconveniencing" anyone else first. Basically, I use them as an "emergency" back-up only. Surely this is better than going behind a nearby hedge or wall, as I've seen people of both sexes do, even in towns?
I fully understand the views of those who are registered disabled, and I would never suggest that any non-disabled person abuse the Radar facilities or use them routinely.
The biggest problem with public toilets in general now seems to be the number that have closed (including Radar), or are almost always locked (sometimes with the keys left at a nearby shop etc), due to financial cutbacks, or vandalism. In some areas there is a problem with the metal pipes and fittings being stolen for their scrap value, so the facilities have been closed.
A thread such as this is very useful to wildcampers, so long as it doesn't wander too far off topic.