Are there mobile ULEZ cameras where you live? If so, perhaps you could put a cover over it? This wouldn't be legal unless the plate is legible through a clear panel. But IME with motorbikes the law isn't enforced much because council parking wardens aren't allowed to lift the cover.
Upon further investigation it seems I should have said that wardens employed by councils cannot issue a FPN for obscuring a number plate or for not having a number plate. They are supposed to tell their control room, which reports it to the police.
Are there mobile ULEZ cameras where you live? If so, perhaps you could put a cover over it? This wouldn't be legal unless the plate is legible through a clear panel. But IME with motorbikes the law isn't enforced much because council parking wardens aren't allowed to lift the cover.