There is an easy fix for all of the unsafe trailers/caravans – make it mandatory to have them registered and get an annual MOT’d like cars.
Its what my sister has to do with her trailers and caravan in NZ, they get a coloured sticker/plate attached showing registration and MOT status, bit like our old tax disc – the police following a trailer can see at a glance if its the current years colour. She moans about the extra cost of getting them tested, but at least they meet the safety requirements every year.
In life, it's not who you know that's important, it's how your wife found out.