Our 2010 Prius manual states that cell phones should kept at least three feet away from the key fob - or time and space will fold in on itself. Why does Toyota do these things?
It just says that it will deplete the battery quicker, no mention of time and space LOL. I keep my key fob in my shirt pocket, alongside my mobile phone, all day and apart from a couple of small temperal disruptions I've seen no ill effects on space, although time does seem to slow down at work.
I'm guessing the phone keeps the fob "active", running it's battery down faster. Hmm, my wife has cell phone and fob in the same purse, not good?
I forget the page number, but within the first 100 pages of the owner's manual, Toyota suggests that for maximum FOB battery life, cells and FOBS be kept apart. I keep my cell and FOB in the same pocket and I'm still alive, but I may have sucuumb to a time warp continuum distortion. Happy Motoring, Tom
Last bullet point on page 64 of my manual addresses the electronic devices not to be in close proximity to fob.