Maybe a stupid question/observation but if you keep your fob in the truck and lock using the exterior keypad...and someone gets into your truck (I.e. Breaks a window, etc...) that will set off the alarm correct?
Assuming the alarm goes off as it should, can the bad guy simply push the start button and drive away without first clearing the alarm through the key fob?
IMO, if you want to keep an extra fob in the truck w/o the obvious risks, why not take the battery out of the spare fob? If you ever need it to start up the truck, use the cup holder location to insert the spare. It's designed to start using that method if your fob battery dies, right? Or hide the battery separate from the spare fob...or both, haha!!!
No offense, but using foil to wrap your $70K spare key fob is....uhhh...not smart ��