I purchased a BMW X5 which is 4 years old. It comes fitted with a detachable tow-bar which is manufactured by Westfalia.
I have towed with this tow-bar about 12 times and on the detachable part of the tow-bar is showing excessive signs of wear and is moving about inside the cone shaped sleeve, which then makes a very annoying banging sound whilst towing my caravan. I would certainly consider these facts when choosing a tow-bar and choose a different make. I have contacted Westfalia uk limited who have sent photos to westfalia in Germany but because the tow-bar is over two years old they are not interested in replacing the tow-bar FOC.
I have since ordered a new tow-bar from PF Jones in Manchester whos service and price was excellent, I would defiantly recommend them.