I recently got bored and came up with this idea to make a key out of a stubby screwdriver and a spare.
started with this. I heated up the hardened steel flat-head to melt the plastic inside the handle enough to pull it out.
I went to Kobeys swapmeet in san diego and got Lyle the key guy to make a copy. He did this although his key guide said not to make a copy because our keys have transmitters. well they don't. My dremel broke so I had to hold the spare with some vise-grips and file the handle of the spare down until it was just barely bigger than the hole. all I did after that was hammer that stuff in.
this is what I ended up with
my next fun key project is to make one out of a 2-in-1
it should be easier