I own a 2003 Lexus RX300 and have been advised I need to consider replacing the battery. I've had it tested at three location with each location offering a different opinion. Consumer Reports lists the Kirkland battery from Costco very high but they do not install batteries. Can anyone tell me is there anything very difficult in replacing a battery on a RX300? Also, can you tell me the CCA's on an OEM battery for this model. The dealer I spoke to says it's "around" 560 CCA's.