1) Yes, but factory batteries suck. I'd get an aftermarket one.
2) A battery saver is essentially a temporary device that makes the car thinks a battery is still connected and gives it enough juice so that you don't lose your memory settings while changing the battery. No need for one of those. You'll have to input the navi/radio code, but you won't lose your seat/radio settings or anything.
I just changed my battery from a factory one to an aftermarket one because the factory battery arbitrarily decided to discharge with no good reason. I had the battery tested and was told that it was fine, and that it just needed to be charged. I didn't want to take a chance being stranded somewhere, so I ended up getting a battery at Autozone. All I had to do was put in the radio/navi code, but none of my settings were lost. Your MID does reset though.
Last edited by turbo_oxide; 03-17-2012 at 02:00 PM.