I've got a Terrano as well. Circa 1995. Got mine from Towequipe. Great price, superfast delivery and simple to fit. The towbar just bolts onto the brackets already on the car (all nuts and bolts supplied. The electrics are are also supplied with the kit and are straight forward). They even have your specific wiring details and tips on how to on their site. Just had a quick look for you and you can get the complete Bosal or Westfalia swan-neck kit for around £107. That includes everything you need to fit it and a free helpline. Their website is here: Towequipe
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.