Moin, I have an upgrade voucher from Sixt here, which can bring me a free upgrade by a class if there is something suitable. As I was quite impressed by the new BMW F10, I would like to get it again at the next rent and to use the class PDMR (BMW 520d/523i/MB E200/E220/E250/Audi A6 2.0). By upgrade it would be the six-cylinder versions, group LDAR. However, since this has become quite rare, the Question whether it makes any sense to use the voucher in this case. If I also receive it with the booked class PDMR, can I then use the voucher to pay a class of low FDMR (BMW 3 Series, MB C-Class, Audi A4) and receive PDMR? Questions about questions. Greetings Mirco