Fob sliding out of pocket

Not sure what has changed, but when the Prius key fob is in the (front) pocket of one of my pairs of pants, and I sit in a particular chair which tilts back slightly, the fob sometimes slides out of the pocket onto the chair. So far it has done it three times, and all three times I only realized it after going out to the car and not finding the fob in my pocket. The odd thing is that both the pants and the chair are old, the other objects in that pocket are my change purse and key case (both leather and the same as they have always been and the fob is placed beneath them), and the fob never used to do this.

So now I'm trying to think of some way to more firmly secure the fob that won't make using it too much of a PITA.

1. I have seen the threads where people attached the fob to a key ring via the little metal loop - and found themselves with the metal key, but without the fob, after something or other pushed the release button. (It may have been a different generation Prius.)
2. I could make a style change and only wear cargo pants with pockets that fasten shut.
3. There are key fob holders but since this car doesn't have SKS, that would mean moving the fob in and out of the case a lot. Anybody ever tried one?

This makes me pine for the days when cars just had keys, because those could go in with the other keys and didn't present any special problems. Well, other than sometimes all those keys dangling on my leg while driving a car.

 

I do have some pants like that and already slide the FOB into that little pocket when it is available. The pair in question is by "Hunt Club", which I seem to remember was a JC Penney house brand. I must have had these a long time... The pockets are plain, no little pocket inside.

There are a few belt mount fob holders. Here is one for the law enforcement market (notice the list of vehicles supported):

Duty Belt FOB Holder – Ultra Light Options

I think pretty much all the fob holders I have seen would be good with the "in the car is good enough" sort of fobs, not so great for "have to put it in the slot" fobs, where it would need to go in and out of the case all the time.

 

Technical question about the fob. It has no external electrical connections, yet it must be inserted into the slot (non-SKS car) for it to start. Presumably the car is talking to the RFID chip and it also checks that the fob is in the slot and locks it in place. If a dummy fob was inserted into the slot (for instance, an empty case) and one held the real fob "close" to the slot, would the car start?

Product tag RFIDs have quite a long range (from 1 to 6 meters, depending on the frequency), but the ones used for "tap to pay" only work over "several centimeters". The tech in a gen 2 Prius predates the "tap to pay" by about a decade, so I'm guessing it has a range or at least a meter. For that matter, is the RFID technology used in the Prius the same or different on regular and SKS models?

The seed of an idea being that perhaps a regular fob might be coerced into starting the car from a holder in a pocket or clipped to a belt if a dummy fob was inserted into the slot. If that was the case, the fob wouldn't need to be moved in and out of its holder ever.

 

Not entirely sure of the geometry you describe. If it means rotating the key 180 around its long axis, with no other motion, then it doesn't make sense. The RFID chip definitely isn't picky like that because a Prius fob can be inserted in either orientation (same rotation as above) and still work. I wonder if the key you had made put the RFID on one side of the metal blank. The RFID transceiver for the slot is, let's say, only above the slot. So in one direction it can see the RFID chip, but in the other it is masked by the rest of the key. A car designed to use a key like that may have two transceivers, or maybe it puts a slab of metal in the right place to bounce the signal via an alternate path to the transceiver.

If you meant rotate the key 180 around an axis perpendicular to the plane of the key, so that the head with the RFID chip was now facing away from the dash instead of towards it, and then it didn't work, that is entirely believable since the transceiver might have a narrow angle where it works, or a range of only a couple of centimeters like a tap to pay terminal.