Inheritance, Polymorphism, Interfaces in VB.Net Classes / Nested Classes for ASP.NET

<%
	Namespace Cars
	
	Public Class Car
		Implements ICar
		
		Protected oDoorFrontRight, oDoorFrontLeft As IDoor
		Protected oDoorRearRight, oDoorRearLeft As IDoor
		Protected oDoorHood, oDoorBoot, oDoorFuel As IDoor
		Protected oEngine As IEngine
 
		Protected Friend Function Make() As String
			Return strMake
		End Function
 
		Protected Friend Function Model() As String
			Return strModel
		End Function	
 
		Protected Friend Function Year() As Integer
			Return intYear
		End Function		
		Public Sub New()
			oEngine = New CEngine()
			oDoorFrontRight = New Door()
			oDoorFrontLeft = New Door()
			oDoorRearRight = New Door()
			oDoorRearLeft = New Door()
			oDoorHood = New Door()
			oDoorBoot = New Door()
			oDoorFuel = New Door()
		End Sub
		
		Function Running() As String Implements ICar.Running
			Return oEngine.Status
		End Function
		
		Protected Friend Function NumberPlate() As String
		Return "AAA000"
		End Function
		
		Public Interface ICar
			Function Running() As String
		End Interface
		
		Public Interface IDoor
			Property IsOpen() As Boolean
			Sub Close()
			Sub Open()
		End Interface
		
		Public Interface IEngine
			Inherits ICar
			Property HorsePower() As Integer
			Sub StartEngine()
			Sub StopEngine()
			ReadOnly Property Status() As String
			ReadOnly Property StartCount() As String
			ReadOnly Property StopCount() As String
		End Interface
		
		Public Property Boot() As IDoor
			Get
				Return oDoorBoot
			End Get
			Set(ByVal Value As IDoor)
				oDoorBoot = Value
			End Set
		End Property
		
		Public Property Engine() As IEngine
			Get
				Return oEngine
			End Get
			Set(ByVal Value As IEngine)
				oEngine = Value
			End Set
		End Property
		
		Protected Class CEngine
			Inherits Car
			Implements IEngine
			
			Private dblHorsePower As Integer
			Private blnOn As Boolean
			Private intStartCount As Integer = 0
			Private intStopCount As Integer = 0
			
			Property HorsePower() As Integer Implements IEngine.HorsePower
				Get
					Return dblHorsePower
				End Get
				Set(ByVal value As Integer)
					dblHorsePower = value
				End Set
			End Property
			
			Public Sub StopEngine() Implements IEngine.StopEngine
				blnOn = False
				intStopCount += 1
			End Sub
			
			Public Sub StartEngine() Implements IEngine.StartEngine
				blnOn = True
				intStartCount += 1
			End Sub
			
			Public ReadOnly Property Status() As String Implements IEngine.Status
				Get
					Return "The engine is running: " & blnOn & "<br/>"
				End Get
			End Property
			
			Public ReadOnly Property StartCount() As String Implements IEngine.StartCount
				Get
				Return "The engine has been started " & intStartCount & " time(s).<br/>"
				End Get
			End Property
			
			Public ReadOnly Property StopCount() As String Implements IEngine.StopCount
			Get
				Return "The engine has been stopped " & intStopCount & " time(s).<br/>"
			End Get
			End Property
			
		End Class
		
		Protected Class Door
			Implements IDoor
			Protected oDoorhandle As DoorHandle
			
			Private blnOpen As Boolean = False
			
			Property IsOpen() As Boolean Implements IDoor.IsOpen
				Get
					Return blnOpen
				End Get
				Set(ByVal value As Boolean)
					blnOpen = value
				End Set
			End Property
			
		Public Sub Close() Implements IDoor.Close
			blnOpen = False
		End Sub
		
		Public Sub Open() Implements IDoor.Open
			blnOpen = True
		End Sub
		End Class
		
		Protected Class DoorHandle : Inherits Door
			Public Sub Lift()
			Me.Open()
		End Sub
		
		Public Interface IDimensions
		
			Property Height As Double
			Property Width As Double
			Property Length As Double
		
		End Interface
		
		
		Protected Class Dimensions
			Implements IDimensions
			
			dblHeight As Double
			dblWidth As Double
			dblLength As Double
			
			Property Height() As Double String Implements IDimensions.Height
				Get 
					Return dblHeight
				End Get
				Set(ByVal value As Double)
					dblHeight = value
				End Set
			End Property
 
		End Class
		
		End Class
	End Class
	
	End Namespace
 
%>