That aerial photo taken yesterday is a superb shot
http://www.pprune.org/9374237-post1448.html and shows very well what is taking place at the airport. (note the traffic congestion)
The 18 million capacity with the upgrade includes the stands so everything will be in place to achieve 18 million without building on the short term car park. Also don't forget the Eastern Apron gains 2 stands as does the Southern Apron. Stands 16 to 20 go back to airline use and the hangar line also gains a stand so that's 9 extra stands.