Not sure. I guess it could be something you calculate yourself if you know how big your exhaust fluid tank is. If you subtract the amount of liquid left in the tank it should give you the top up number.
Side note, apparently some people are complaining about rattling sounds coming from the boot area when going over bumps. This could be caused by loose Ad Blue tank and one fix was for the dealership to replace the acoustic padding tape that has come loose.
Can confirm that re-filling the tank yourself is an absolute cinch if you buy the custom made filling hose ( see AdBlue on BASF website ). Tank is 17 litres total and is easily filled in 15-20 minutes. This does not need to be done by the dealer.
The above issue of the rattling sound is indeed caused by the AdBlue tank coming loose and is a recall in Europe.
My XE turbo diesel is still on order, so I haven't had the opportunity to check on the ad blue tank, but on my Mercedes Turbo Diesel it is easy enough to top up the ad blue tank. I purchase the Ad Blue fluid at Wal Mart and it's relatively inexpensive and comes with a plastic tube to use for filling your tank. Not a problem at all.