gistfile1.cs

public class SuggestionController<T> : ApiController, ISuggestionController<T> where T : ISuggestion {

	public ISuggestionSubmitter<T> Submitter { get; set; }

	public SuggestionController(ISuggestionSubmitter<T> submitter) {
		Submitter = submitter;
	}

	[HttpPost]
	public JsonResult Create(T suggestion) {

		if (!ModelState.IsValid) {
			Response.StatusCode = 422;
			return Json(ApiResult(ModelErrors()), JsonRequestBehavior.AllowGet);
		}

		T result = Submitter.Submit(suggestion, CurrentIdentity);

		return Json(result);
	}
}

public class ModelSuggestionController<T> : SuggestionController<T> where T : ModelSuggestion {
    	
		public ModelSuggestionController()
			: base(new ModelSuggestionSubmitter<T>()) {

    }
}

// Final Impl

public class CarModelSuggestionController : ModelSuggestionController<CarModelSuggestion> {
    	
}