How early can dealers register a new vehicle?

When is a main dealer able to register with the DVLA a brand new vehicle he has on order in my name?

How do I know a new reg car isn't several months old?

If you order a new 74 plate car how do you know that it was not sat in the forecourt for many months?

If I order a new car for delivery in nine months, will my part-ex value change?

If I order a new car with a nine month delivery time, can I get an agreed price for my current car or will it depend on its market price when the new car is ready?

When can we see Fisker cars in the UK?

Where can we actually see Fisker cars and sit in etc?