You really need to read the terms and conditions of your contract with ford and mb.
Any fees should be Listed in that, you should of been made aware of them all at the time of signing up them to order the car..
I cannot say i have heard of such a case, but that don’t mean it cannot happen. although a contract has to be lawful and i doubt a fee of 2.5k would be deemed as reasonable, unless the car is already registered to Mb and ready to pickup then there could be losses on the part of the dealer, They would have to bring a claim against your in court. if you did not pay or if they keep your depoist(if you paid one) then you will have to make a claim against them.