I sold my Skoda Fabia a year ago, a week later the chap who purchased it came back to me complaining that the gear box had gone. He wanted his money back. I contacted citizens advice bureau who said as I had put sold as seen I was in a much better position, and all he could do would be to take me to court. I told him this - he told me to f*ck off and said he would come round my house every day until he got his money back. I told him I would put the kettle on. He turned up 3 days on the trot and had a rather heated chat (over a cup of tea.) Unfortunately he was a 6'3, rambo esqe guy who was a bouncer for a club in Soho. I said as he was a nice, genuine guy, I would give him £250 if he would sign a declaration to never contact me again and f*ck off. He did and I've never heard from him since.
Was quite funny as when he arrived on one occasion and put his motorbike helmet down next to my 10 year old sister bright pink, flashy cycling helmet. As he went to pick up his helmet I said 'make sure you pick up the right one.' He didn't find it very funny though. I lol'd.