Install is finished, and everything works great!! Definitely impressed with the design and and hardware in this mod. In my opinion, way easier than using a blank CD. My install is pretty much identical to angeltalin's in switch and audio placement. Works as advertised, with no problems to speak of.
The most difficult part was actually finding the 20mm drill bit. Went to 5 different stores, not a one carried any metric bits. Ended up using a 3/4" bit, then using a small sander to widen the hole. Not perfect or as clean as I would like it, but can't tell with the switch in, and it's tight, not going anywhere. And I must admit, it is a little intimidating removing that much of the interior and disassembling the radio (might have payed a guy to solder the wire... figured it was worth it to avoid destroying my radio), but it went back together with no problems whatsoever!
Thanks to RedFloyd for a great product, and thanks to everybody on here for the advice and ideas.