I am confused here by the fact that youre being asked to pay £1500 more for a used car ??

I cant see how that works, even though the estate is bigger & more expensive, in reality it is still a used / second hand vehicle, I would have expected as a pre reg / used/ 2nd hand car to have it at the price & contract you have agreed. If they want to throw in 3 yrs servicing as a 'Sorry' then fine.

Just my 2p

Surely this is breach of contract by the dealer?

Why negotiate ? Tell them if they don't supply the car you ordered on the delivery date then you will take them to court.

Go and see a solicitor it may cost £50 for them to send a letter, dealers always keep the people who shout loudest the happiest.

Don't worry about dealer relationships......The salesman, sales manager, dealer principal and everybody else in the dealership go to work to make money not friends.

If you PX your car and they got more for it than they thought at auction would they send you a cheque for the difference?

I worked in sales at a main dealer for years and ive seen both approaches and seen what works best.

There is no breach of contract here. They have agreed to supply the car as ordered, the 'contract' will have an expected delivery date only. They would still have supplied the car as agreed if the OP wished, but the expected delivery date will be revised.

you shouldnt have to do anything. its their **** up. my father in law ordered new e class with loads of spec to collect from factory in germany. salesman ordered sunroof instead of panoramic roof. the dealer ordered anew car for him but with right roof let him drive round in wrong car until new car was ready. he went to germany again to collect. the dealer paid for his wife to travel second time as only driver gets to go free. they didnt take any extra money off him and gave hm first service free.

you shouldnt have to do anything. its their **** up. my father in law ordered new e class with loads of spec to collect from factory in germany. salesman ordered sunroof instead of panoramic roof. the dealer ordered anew car for him but with right roof let him drive round in wrong car until new car was ready. he went to germany again to collect. the dealer paid for his wife to travel second time as only driver gets to go free. they didnt take any extra money off him and gave hm first service free.

Mercedes say no more, if they can afford to do things like that , the car prices are definately way over the odds, we know their servicing is well overpriced from SWMBO previously owning a Smart.

Its their screw up.

I would offer the extra £1500 as a gesture of goodwill but would want it on 0% finance and be the first owner. If they don't agree, make them re-order the car with the same deal as per the contract and they give you a loaner for the period of the order.

Its not your fault they have screwed up. Play it to your advantage.