Hello Andrew,
I'm sorry but its not possible to give a reasonable answer to your question. The maximum allowed towed weight that a car can handle is not uniform across a whole model range. It is specific to each model and can change depending on year, body style, and of course engine variations.
Similarly each caravan model has its own ratings, again which can vary depending on year and other body styles.
So we need more information to be able to offer any kind or safe advice.
I also have to add that information supplied in replies on this and other web sites may not be accurate, so it is important that you double check facts and weight limits on the vehicle data plates or with the manufacturer.