My wife and I have a 2011 and a 2013 prius. I drive the 2011 and when she gets in to ride with me , her key fob interfers with mine . The 2011 will say "no key detected-touch key to start button" which is annoying and sometimes takes 3 or 4 tries to get it to work. I thought my batteries were low so I put new batteries in .but it did not help,however when I ride in the 2013 there doesn't seem to be a problem. I have also had my wife put her purse in the back seat and still had problems. Just wondered if anyone had any ideas that might help?
You need to find a metal box or container to put her fob in when she is in your car. Or, wrap it in some foil. SCH-I535
I wonder if there's a purse that has various compartments, one of which wrapped with some kind of foil fabric (or similar, or metal). She puts the fob in that compartment when riding in your car and in the other compartments when in her own car.