I have had a hema navigator for about 3mths now and am on my 3rd 12v power supply. The plug in the end keeps geting loose and breaks the positive wire off it. My first one when i bout it didnt even last 400km into a 2000km+ trip. The others lasted a bit longer but not much. I know shane308 has had the same trouble. We both went to dick smiths and bought new 12v plugs. Shanes didnt work, mine did at first but then the light started flashing the same as what happend to shane.
Ended up making one out of the 2. Soldered the wire and plug from the motorola charger into the circuit board from the hema charger and all works fine.
I should also add that appart from this issue i have been impressed with the rest of the unit.