The word that's eluding jokiin is "discontinued" the Markus 5 dident really take off as i undestand it, allso think there was a little issues with it as there seem to be / have been with most dual camera systems.
I suppose that will allso mean the end of firmware support for the Markus 5.
I dont like any of them as they are too large, and if you install / remove it for each drive i think its too much work with wires to plug in and so on.
Much better alternatives should be out in 2016 and the issues with current models should be ironed out better, or replaced with new hardware.
I suggest, get a cheap camera like a Mobius to have while you wait for better options.