The car will go to the dealership, fiat do not directly sell you a car they use franchised dealers which are technically not part of or owned by fiat to sell their cars. So the car will go to the dealership from whom you bought the car.
They will then do all the pre-delivery inspections and fix anything that's not 100% then deliver the car to you or have you collect it from the dealership.
The cars are transported in to the uk by ship as fiat doesn't make any cars in the uk and will be transported around the country on lorries.
A company like Mini had its own custom rail carriages to move their cars to the ports for transport out of the country on ships when exporting to other countries. The milage that will show on the car when delivered is put on by it being driven on and off ships, around storage yards and on and off lorries as well and a few miles for the PDI