I am a flat owner and per the land registry I also own my parking space.
UKCPM recently took over control of our car park and their signs explicitly state "display a valid UK CPM permit in the windscreen at all times". Note they don't specify front or rear windscreen.
My permit was on display in my rear windscreen due to visiblity concerns in the front. You can see the permit in UK CPM own photos.
My appeal was rejected (but reduced to £20 which I am still very much against paying)
My details are not being recognized by IAS appeals and UK CPM say they are unable to help on the phone.
Any advice would be appreciated.

Here is the permit on show in their own photo:
Welcome. Do you own your flat and parking space on a leasehold basis? If so, what exactly does your lease say about parking?
Welcome. Do you own your flat and parking space on a leasehold basis? If so, what exactly does your lease say about parking?
I can't find any specific regarding parking but yes I own both on a leasehold basis. My lease confirms that the parking space is allocated exclusively for my use as in the Land Registry.