Similar questions have been asked many times over the years and although impossible to give a definitive answer, there are factors which could affect this. The discount offered by VW, the projected future value, maintenance costs, insurance etc. There does appear to be little logic sometimes. Another way of looking at it is to add the weekly rental, PIP, to the AP and you get 11399 and 15899 or 12849 if you take the cheaper id4.