I have an existing Motors Classified listing and would like to add another category. The category I wish to add is Motors > Cars, Motorcycles & Vehicles > Classic Cars > BMW [which exists] but it does not offer me anything under the Motors > Cars, Motorcycles & Vehicles directory tree. It offers me lots of others under Vehicles etc... which isn't what I'm looking for. Are there certain category trees that can't be added after a classified listing has been done or something ?