OK so I got my ODBlinkMX+ today and magically the AH number appeared... Yeah....
I have 2x2012's and the results are:
95000 KM one gives 36.0 AH
50000 KM one gives 37.3 AH
It's also pretty cold now -4 deg I would expect that number to go up in the spring and perhaps dip more in the summer.
It's interesting to see that for almost double the mileage the difference is 1.3 AH or about 1.3AH*360V/120WH/KM ave summer = 3.9 KM difference in the cars. If a new car is 45.8 AH then i have lost 22% and 19% maybe less in the summer if the car is adjusting for temperatures.