Fail-safe for keyless entry

["Robert Green" <robert_green1963@xxxxxxxxx>]

I've got the typical minivan keyless entry keychain fob but it's got a
serious design problem.

The buttons depress too easily and often accidentally when the fob is pushed
into a pocket or a purse.  It's happened more than once, so it's time to do
something about it.

The real estate inside the fob is very cramped.  It runs off a CR2032 coin
cell battery, and the circuit traces are simple enough so that I could
scrape off the 3VDC+ line and bridge it with a small switch.  That way, I
could just put in a tiny pushbutton that had to be depressed as well as the
desired command button each time a command was sent.  That approach makes it
a two-handed operation, whereas a slide type ON/OFF switch could still be
worked with one hand.

The problem is that I don't see any space in the fob for the kinds of
switches I am used to.  The ideal solution, of course, would be for the
manufacturer to put something that's found even on most throwaway $10 MP3
players - a hold button that locks out the buttons when so desired.  You'd
think with what they charge for a replacement fob they'd include something
like that.

I *might* be able to work a small slide or lever switch inside the fob, but
it's tight.  In the interim, I made a clamshell type case made of hard clear
plastic bubble packing material and one of those retracting string keychain
things so I can slide it out to activate it and then let the rewinding
mechanism withdraw it.  So far, the hard plastic sheath has reduced the
accidental openings, but it's butt ugly, ungainly and not a very good
solution.  Plus, it came unglued more than once.  There's a lot of
interesting stresses in pockets and pocketbooks.   Ideas, anyone?

Thanks in  advance!

--
Bobby G.