Car Will Not Start problems of the 2013 Lexus GS350

I purchased my brand new Lexus ES 350 less than three weeks ago. The car has less than 500 miles. The car was sitting in my garage for three days and now is completely dead. Had to call road side assistance. The battery was completely dead and the car could not start. The issue with the battery is not due to any lights being on. The car lights were completely off but battery drained anyway. I just found out from other Lexus owners that this is a flaw with Lexus cars. The battery runs out due to some malfunction.