Wouter...the "holdback" is an american dealer term ,it refers to the holdback of money that the factory held , so the dealer could get 'free', not being part of the 'invoice' that the salesmen saw , since they got paid usually in a % of profits, = difference between 'cost' , (invoice) and sale , sales amount...

I dont have the dealercodes to tell you which dealer it was , but that number should be the same as the name of the dealership that sold the car, should be on thee too...the Zone , I have no idea how Pontiac divided up the country...I know how Volvo does..lol