The time has come to go from 2 cars to 1 MPV. We have decided on a Citroen C8 Diesel against which we will P/ex our existing cars (we've got OK values for these). The question is, Citroen offer some big discounts above the cashback offer. How do I best negotiate a good deal? Really not very good at this haggling business but cannot afford to pay more than necessary (need more bikes!). Any experts?