Picture this: you’ve done your homework, walked into your local BMW or Mercedes dealer and thanks to some pro haggling have managed to secure a great deal on your new M2 or E-Class. All you have to do now is wait for delivery in around three months time. But then you get hit with a double whammy.

The dealer calls to tell you that the car is delayed. The wait is going to be more than four months. Oh, and that price you thought you’d locked in when you signed that paperwork? It’s gone up.

BMW and Mercedes are only currently only guaranteeing prices for four months, according to Germany’s Automobilwoche, and it’s not hard to see why. Inflation is currently running at over 10 percent in Germany and the UK, and more than 8 percent in the U.S.

Related: Soaring Prices And Interest Rates Send Many Monthly Car Payments To Over $1,000

Mercedes’ contracts are harder to exit, report claims

It’s proving difficult for carmakers to make accurate long-term predictions about the prices of raw materials and carmakers need to make sure they’ve got their financial asses covered. Other factors that could send prices north include rising interest rates that can have a dramatic affect on leasing and financing calculations.

Automobilwoche reports that any affected BMW customers unhappy at being asked to pay more for their car can cancel the contract, though we imagine most will follow through because it’s not like they can buy elsewhere for less. The same report says that Mercedes is less accommodating, and will only allow affected customers to exit the contract free of charge if the vehicle’s price has risen by more than 3 per cent. We’ve asked BMW and Mercedes to clarify if the same policy applies in the U.S. and will add their comments to this post when we hear back.

Would you still go through with a new car purchase if your dealer told you it wanted more money at delivery time than you’d originally agreed to pay? Leave a comment and let us know.