Espritemike, I've done the mod you're asking about. I installed a pull actuator and cable to unlatch door. Added a all weather plunger switch in the handle pocket of the rear door. A micro switch attached to the drivers door power lock arm switches a relay to power the rear door only when doors are unlocked. And I added a plunger switch in with the doom light so if rear door is opened alarm will go off. I've had it in for 3 years now and it still works fine.
You can see pics in my gallery, I can't seen to load them in this post for some reason....