We've just had a situation where a customer ordered their car last month (price protected - no problem there) but called up this week to add an option. Whilst we can amend the order still, Volkswagen consider this to be a new order and because a new order form will have to be signed, they have advised us that the customer will now be succeptable to the price increase! Hence the sunroof the customer wishes to add, would actually cost about £1200 including the price increase.
He didn't add the sunroof!. Sadly there is nothing we can do in that situation.

but worth knowing if you are tempted to add anything to your orders after they have been placed.
VWmd