Scheduled for production really depends on how backlogged the orders are. Mine was about 2 weeks when it changed from Scheduled to Ready for Shipment, as I recall. However, it seems from several reports that their web site is about 7 - 10 days behind what really is going on - that was my experience too. Your car could actually be in production right now, or maybe even completed.
The car has to go from the factory, presumably in Bavaria, to the North Sea by truck or rail. Then it gets put on the next ship, floats across the pond and has to go through customs and the prep center before it gets to your dealer.
If it hasn't gone into production yet, I think it's questionable that it will be here in 4 weeks. I did my car via European Delivery, so I know exactly when it shipped and arrived. It took about 4 weeks just for the shipping/delivery process.
But if the web site is really behind 7- 10 days, you might still be on target....Let us know!