http://www.perthmilitarymodelling.com/newkitnews/roden.html
Roden have announced what is called a RR 40/50 Silver Ghost in 1/35 scale - no idea if it will be using parts from their existing RR armoured cars.
Also noted Tommys War announced two versions of the Thornycroft J, the G.S and the 13pdr AA. 1/32 scale
http://www.perthmilitarymodelling.com/newkitnews/tommyswar.html
Paul
The finest stories of the Great War are those that will never be told.