Rear living area small shelf in sliding door?

[mallo]

Sat in the back of Cali today with the Missus after a day out and enjoying a brew. It dawned on me that I could do with a small tray/shelf on the off side sliding door projecting inwards from the rear of the sliding door window, to hold a mug and biscuit when inside. I appreciate that it would only be temporary as it would interfere with the door. It would only be a nice to have and probably doesn't need to be that big. To the rear of the opening are 4 holes in the lower rail for securing the window when opened and i thought could use these somehow. I'm now in the planning stage but has anyone else fabricated such an item? Failing that we'll just have to pass each other stuff off the fridge/sink unit.

 

[BMVS-Camper-Hire]

If you slide the seat all the way back with the bed ase upright, there is a cup holder at the bootom, behinf=d the door opening, but you sacrifice boot space then.

Be intersted to see what you come up with.