lemikus

I purchased a used 2014 GS350 with push button start. If I am hiking in the boonies and lose my fob, I need a way to start the auto. For other Lexus' I have owned, I purchased a valet key and taped it to the undercarriage for emergency use. However, the GS350 will only start with an appropriately programmed fob. I am thinking for the GS350 to purchase an additional fob & blade and have the fob programmed and blade cut. I would put the fob in the glove compartment in the battery saver mode and tape the blade to the undercarriage. I have tried this with my existing 2 fobs and as long as one of them is in the battery saver mode, there seems to be no interference and everything works normal with the other fob fob. Am I missing anything and is there a simpler way to start the auto in an emergency without a fob?