Can't fit a dremel in your pocket? heehee
I know of these screws--a major PITA. I remember that I drilled the heads off a couple to get a slave CD out of a '91 Lebaron. Wasn't too hard, but because of space restraints, I could not get the rest of the screw out. Though it should have turned easily with the head and cd player gone, it didn't move at all with a needle nose pliars. But I didn't care. I shoved a dummy plug in place of it and let it head out to the wholesale lot.
Then, I went after a head unit in a '95 Concorde, and it had them as well. I wish I remember how in the world I got them out with a basic tool set (maybe it was just a pair of vice grips?) but if the head is round and tapered, that couldn't have been what I used. I am also interested in getting this tool.