The
problem is no one knows what is going to happen yet. SEAT didn't mention anything regarding the import charges when I asked them. I would wait and see when your build date is first.
The debatable question is you signed a finance agreement saying 'X' amount initial rental and 'X' amount per month. If this increases significantly how can affordability be justified for everyone? I for one couldn't really afford that jump of upto £3k. The whole reason for this lease was due to the cheaper costs.
Also with myself if the dealership had ordered my car when they were supposed to it wouldn't be delayed by 3 weeks so I could easily argue my case. I ordered the car on the 12th July but they didnt actually order the car with SEAT until the 2nd August.