LINQ组列表<；对象>；基于基类属性

我得到了一个List，在其中我放置了超类中子类的实例。

我的课程代码：

public abstract class Vehicle : IComparable< Vehicle >, IComparable 
{
    public string Manufacture{get;set}
    public Int16 VehicleID{get;set}
    public DateTime ProductionDate{get;set}
    public Vehicle(Int16 _ Vehicle ID,DateTime _ProductionDate)
    {
        this.AccidentID = _ AccidentID;
        this.ProductionDate = _ProductionDate;
    }
    int IComparable.CompareTo(object other) 
    {
        return CompareTo((Vehicle)other);
    }
    public int CompareTo(Vehicle other)
    {
        return this.ProductionDate.CompareTo(other.ProductionDate);
    }
    public Vehicle()
    {}
}
public class Car : Vehicle
{
    public Car ()
    {
    }
    public Car (Int16 _VehicleID,DateTime _ProductionDate, Int16 _CarAttribute1, Int16 _CarAttribute2):base(_Vehicle ID,_ProductionDate)
    {
        this.AccidentID = _ AccidentID;
        this.ProductionDate = _ProductionDate;
        this.CarAttribute1 = _CarAttribute1
        this.CarAttribute2 = _CarAttribute2
    }
    public Int16 CarAttribute1{ get; set;}
    public Int16 CarAttribute2{ get; set;}
}
public class MotorCycle : Vehicle
{
    public MotorCycle ()
    {
    }
    public MotorCycle (Int16 _VehicleID,DateTime _ProductionDate, Int16 _MotorCycleAttribute1, Int16 _MotorCycleAttribute2):base(_Vehicle ID,_ProductionDate)
    {
        this.AccidentID = _ AccidentID;
        this.ProductionDate = _ProductionDate;
        this.MotorCycleAttribute1 = _MotorCycleAttribute1
        this.MotorCycleAttribute2 = _MotorCycleAttribute2
    }
    public Int16 MotorCycleAttribute1{ get; set;}
    public Int16 MotorCycleAttribute2{ get; set;}
}

我希望能够根据基类（即Manufacture）中的属性对这些实例进行分组。

public class Grouping<K, T> : ObservableCollection<T>
{
    public K Key { get; private set; }
    public Grouping(K key, IEnumerable<T> items)
    {
        Key = key;
        foreach (var item in items)
            this.Items.Add(item);
    }
}

• 更多信息，请访问：http://motzcod.es/post/94643411707/enhancing-xamarin-forms-listview-with-grouping-headers#sthash.kWyEfaqU.dpuf

类似的东西

var sorted = item in allVehicles //including cars and motorcycles
    orderby item.Manufacture
    group item by item.Manufacture into vehicleGroup
    select new Grouping<string, object>(vehicleGroup.Key, vehicleGroup);

欢迎提出任何建议：）