Polymorphism

Hi

I would like to know how can i implement polymorphism via the current nopcommerce mode of operation.

for example:
I want to have Wizard base class.
I want to implement different types of wizards. for example- CarWizard, AirplaneWizard, etc.
The Wizard base class contains common fields regarding the CarWizard,AirplaneWizard, etc.

The problem is : When i use Wizard base class in queries(repository), i'm having troubles getting the right concrete class since the entity framework creates different tables for each Type.

remark: most of the fields are common- therefore we want to store the common information in one table.

for example:
Wizard base class contains: Wizard Id, Wizard Type, Name,Creation Time, etc
CarWizard: Number of wheels..
AirplaneWizard: Width of wings..

Thanks,

Saba.