Ok...so after asking around this forum and doing a bit of research elsewhere on the web, I've finally succeded in hardwiring my Escort 8500 to my R1200GS, and as a bonus, I've made it actually look somewhat nice, I think. I've had it working for a while, but today I finally made it look good, so the dealer wouldn't ask where the bird that lives in that nest is.
Essentially I followed hmarc's recommendations and they worked...perfectly. This has never thrown an electrical fault (a feat of true accomplishment on a 1200GS). I wired in a relay to the infamous blue/green wire on the diagnostics plug, and then on to the detector. As far as hiding the wiring, it's all below the tool pack tray, ironically, where BMW has put what looks to be their own relay.
Hope someone enjoys or finds these pictures useful...don't hesitate to email me with any questions you might have or better yet, any suggestions you might have.