You will get optimum output from your solar panels if you alter the angle during the day. This is explained in great detail by CMCA expert Collyn Rivers in his book Motorhome and Caravan Electrics Too. Collyn has also provided charts listing hours of expected sunshine at various places at different times of the year. An approach used in the USA is to use old Winegard TV aerial raising mechanisms. This is a great idea as you can raise and lower from within the vehicle.The big drawback in Oz of course is the high cost of the spare parts bits you need. Aussie ideas are pretty spot on don't you think?