if(name!=null)
{   

       switch(name)
       {   

              case  "Convertible": furtherDiscount = 500;

              break;

              case  "Premium"  :     furtherDiscount = 800;

              break;

              case " GT500"    :     furtherDiscount = 700;

              break;

      }

}

implement some codes of case like this:
case model of

    "Convertible": furtherDiscount = 500;

    "Premium":     furtherDiscount = 800;

    " GT500":      furtherDiscount = 700;

   ...