A couple more from Cardiff (CWL)
Like Leeds, a Hispania 737-300 - arrived from wherever and was impounded, passengers were not allowed to board - Hispania titles were painted out pretty quickly.
Also an Airways International Cymru BAC 1-11-300 - I can remember seeing the paperwork stuck to the aircraft.
I've seen others around the UK, but think they were awaiting new homes, rather than being impounded - Air Europa 757-200 at Cardiff, Capital BAe146-200 at Leeds and Air Europe 737-300 at Bournemouth...