I need to add caravan to car optionsas some routes are not allowed with car and caravan

Sorry, but this is impossible with the basic level unit (nuvi 200/200w/200t) which you own.

You need to use either a multi-mode unit which allows you to navigate as either a "car and trailer" or as a "truck" or to get a "trucking friendly" unit.

Some Garmin units (like my 770T which has much of the same basic software as yours) do have a workaround which can help but is nowhere near as reliable as a proper trucking friendly unit: basically you set the map detail as low as you can accept. By doing this not only are the maps visually simplified by leaving out minor roads but when choosing a route the unit seems to ignore many of the minor roads which are normally a problem when towing.

If you choose to upgrade your unit for another Garmin then you'll discover how useless the company's website is. The specs are listed for each unit, but only say with some models that a unit is not trucking friendly and do not confirm whether others are trucking friendly. Even the multi-mode units do not clearly indicate whether they're suitable for trucking or trailering.

Sorry that I cannot give you a more positive answer but I hope that you have still found my answer to be informative and useful and can return the favour by rating my answer. If my answer has not met your requirements then add a suitable comment and I'll try again.