With reference to the title, any good suggestions?
If no one else is chiming in…
Up until July of '42, the SAS was transported by the Long Range Desert Group (Long Range Taxi Service?) A good general overview of their equipment is covered in Osprey’s “Vehicles of the Long Range Desert Group 1940-45”. Lots of pictures and a number of references to the difference between SAS and LRDG vehicles. The bibliography is limited but it might provide you with a good start point.
Good luck in your search.