I have a 2008 Prius and the for about 2 weeks now it has been spontaneously resetting its memory. I turn the car off as normal, the next time I turn it on it tells me I have no gas, the MPG and Miles have reset, all my radio station presets are cleared. It started after I installed a subwoofer ( but I also installed it a couple weeks after I got it ) I thought the sub was draining the battery, but the car starts fine and shows the battery is one bar from full. So I ruled that out. I have looked on here and Google and I can't seem to find anyone else with this type of problem. Any help would be greatly appreciated.