Mark,
You won't need to be 'fitted' for the car but two things you may want to pursue are: 1) test the different seat options. You will fit differently in cars that have reclining seats (adjustable backs) to ones that do not and (2) you may want to ask the factory to put less padding in the driver's seat.
If you're tall, this is a good idea, otherwise your head will sit proud of the windscreen.
The factory will be happy to entertain this if you ask them when you spec your car.
