I received a few helpful hints on removing my radio, and none of them involved explosives or prybars. (it's held in by a pair of screws with 5-sided heads that look a lot like hex screws at first glance)

Norm Grills suggested wedging a hex key in there anyway and pushing in on the radio as you turn the screw, so as to let the screw turn as easily as possible. Failing that, he mentioned that Bavarian Autosport sells a pent-tool for $16.95.
Dale Beuning also suggested wedging a hex-key in there. And most surprising, the extremely helpful Brett Anderson mentioned that the correct tool is available from a dealer(!) for about $12.50. Sorry I didn't explore that avenue first, as I kind of expected my dealer to disavow knowledge of such a tool, or refuse to let me buy it, or charge $50 to use the tool to loosen the screws, or something similarly silly.

Now we all know. Are there any FAQ maintainers watching?

Thanks all!

• -- John Bolhuis | "On Compuserve, I can type 'go kitchens' and get bolhuijo_at_eit.com | recipes. The Internet is the complicated thing

  | with all the 'w's."

  -Audrey