My Lexus LS 460 sat in the garage for about 10 days. During that time it made only two trips outside the garage to wash it and to move a mower out. It did not drive around at all, just in and out of the garage. When I went to start it after those 10 days, the battery was completely dead. My husband measured 2.9 volts. The battery, which we purchased at Napa about August 16, 2010, was the correct size, and was determined to be just fine by the Napa people. As far as we can tell, no doors were left open, and nothing inside was running. We brought the car to our local very good garage mechanic, who said that "these new cars must be run every 3 days or the batteries will die because there are so many memory things that stay on even when the car is turned off." He said that we need to disconnect the battery if we intend to leave it for 3 or more days. This has never happened to us before. Has anyone else had such a problem? We live 100 miles from our dealer so don't take it there for service if we can help it.