My 20 year old daughter bought a 2nd hand horse trailer last week from a private seller who described the trailer in good solid condition and as having no faults that could not be seen in the photos. When we went to view trailer we noticed one light wasn't working and one tyre looked soft. These were fixed before we picked up and we were also told that her brother in law, who deals in tractors and agricultural machinery, had had a look at it and the trailer only had surface rust that we could see and no major faults. When we picked the trailer up her son and brother in law helped us hitch up and get lighting working with our car. We brought trailer home, parked it in our drive and 1 day later picked up a horse. One hour into our journey home with horse the trailer undercarriage broke and the trailer ran free from the towing vehicle. Luckily no one was badly hurt but the lady is now telling me that she has taken legal advice and doesn't have to give us our money back. I know that trailers are classed as vehicles and that they have to be roadworthy but does anyone have any experience or advice to share?